Extreme Heat in the Caribbean: Impacts on Wellbeing and Buildings Energy Infrastructure—The 2023 Summer Case

In recent years, global climate change has highlighted the vulnerability of regions like the Caribbean to the intensification of extreme weather events, with heat waves becoming more frequent with changing climate [1,2]. The summer of 2023 presents a remarkable case study, as Puerto Rico and the US Virgin Islands (USVI) experienced anomalous weather, which presented extreme heat events exceedingly above historical climatic conditions. Extreme heat events in the Caribbean are not a new phenomenon, but the intensity and frequency witnessed in the summer of 2023 demand urgent attention. For the first time, classes were canceled in public schools as heat advisories and record-breaking temperatures forced government officials to scramble for ways to protect students [3]. Recognizing the urgency of understanding the scientific underpinnings of this phenomenon, this study focuses on the extreme heat observed during the summer of 2023 in Puerto Rico and the USVI, offering insights into the severity, duration, and potential future trends of such events. Summer heat waves, sporadic periods of elevated temperatures outside the normal range of climate variability, occur throughout the world and are projected to become more frequent and intense in the future [1,4].

The heat index (HI) is the combination of the air temperature and relative humidity to estimate what humans feel as an apparent temperature [5]. This has important consideration for the human body's comfort. As the air becomes more saturated with water vapor, the human body becomes less able to shed excess heat through evaporative cooling of perspiration. This can lead to exacerbation of high-temperature impacts such as fatigue and heat exhaustion [6]. For lower relative humidity values, the heat index can be lower than the actual air temperature. The human body feels warmer in humid conditions, and the opposite is true when the relative humidity decreases because the rate of perspiration increases. Unfortunately, there has been an overall moistening of the globe in recent decades near the surface [7], linked to increasing temperatures [8]. These increasing temperatures and relative humidity will lead to increased heat indices. Variations in the heat index are linked to both human health and energy demands to maintain indoor room comfort [9], and hence, it is important to characterize the behavior of the heat index.

The study aims to comprehensively analyze the severity and impacts of heat indices observed during the unprecedented summer of 2023 in the Caribbean region. The objectives include investigating historical heat indices to establish a baseline, characterizing the heat indices for the summer of 2023, quantifying anomalies against climatological norms, identifying contributing atmospheric and oceanic factors, assessing impacts on communities. The research seeks to broadly advance scientific knowledge regarding extreme heat events in the Caribbean region, with the goal of informing resilient and sustainable practices for vulnerable communities and ecosystems in the Caribbean. To guide the investigation, the following research questions will be addressed: How severe was the extreme heatwave in Puerto Rico and the US Virgin Islands during the summer of 2023? What regional patterns of elevated heat were observed in the broader Caribbean context? How do sea surface temperatures (SSTs) anomalies correlate with increased heat indices in the studied area? How did the atmospheric conditions influence the occurrence of extreme heat events? What are the potential socioeconomic and environmental impacts of the extreme heatwave experienced in Puerto Rico and the US Virgin Islands during the summer of 2023, and how can this information be utilized to develop effective adaptive strategies and mitigation measures for vulnerable communities and ecosystems in the Caribbean?

The HI classification (NOAA NWS) into “Caution” (80 °F–90 °F), “Extreme Caution” (90 °F–103 °F), “Danger” (103 °F–124 °F), and “Extreme Danger” (125 °F or higher) serves as a critical tool for predicting the potential physiological impacts of heat exposure. At the lower end, “Caution” suggests fatigue during prolonged exposure or activity. As HI rises to “Extreme Caution,” the risk of heat-related ailments like heat stroke, cramps, or exhaustion increases, necessitating preventive actions like hydration and seeking cooler environments. “Danger” levels indicate a high likelihood of heat-induced illnesses, making preventive measures essential. In the “Extreme Danger” zone, heat stroke becomes highly probable, marking an emergency where the body's ability to regulate its temperature is overwhelmed, requiring immediate medical intervention to prevent severe health outcomes or fatality. Serious illnesses such as heat stroke, heat exhaustion, and cardiovascular and respiratory problems rise during the warmest spells of the year [10].

Small tropical islands are in climactic zones already prone to increased risk from heat stress, asthma, vector, food, and waterborne disease. Changing climate conditions can worsen the impacts of these diseases [11]. The significance of this study becomes even more pronounced considering its crucial implications for public health, particularly in the context of the discussed heat-related illnesses. The extreme heatwave documented during the summer of 2023 in Puerto Rico and the US Virgin Islands poses an extreme threat to the local population's well-being. The study's findings will aid in forming proactive measures to safeguard vulnerable communities, enhance public health preparedness, and prevent adverse health outcomes associated with extreme heat in the Caribbean region. Therefore, the research not only contributes to scientific knowledge but also holds tangible and immediate relevance for protecting the health and well-being of the local population.

We relied on hourly temperatures and corresponding relative humidity data collected from the Automated Surface Observing System [12] stations in San Juan Airport and Roosevelt Roads (Eastern Side of the Island) for the initial analysis. These ASOS Stations provide real-time, high-quality meteorological data [13], ensuring the accuracy and reliability of our analysis. To establish a baseline for our analysis, we examined the historical summer climate of maximum heat indices in Puerto Rico from 2001 to 2020. Similarly, we calculated the maximum daily heat indices throughout summer 2023 and quantified anomalies. Lack of station data for either temperature or relative humidity restricted our initial heat index analysis to only two stations, Luis Muñoz Marín International Airport (TJSJ) and Naval Station Roosevelt Roads (TJNR). To better understand the spatial distribution of heat throughout the islands, the analysis was complemented by local station data that included COOP Stations, indicated in Fig. 1 reporting maximum and minimum temperatures.

The daily maximum heat index value from the calculation is selected for each day. This equation is obtained by multiple regression analysis, and so, the HI has an error of ±1.3 °F.

The heat index analysis is extended over the entire Caribbean region, 90 W to 60 W and 10 N to 30 N, using the NCEP North American Regional Reanalysis² (NARR) dataset. NARR is a regional reanalysis covering North America using a Northern Lambert Conformal Conic grid with approximately 0.3 deg (32 km). The NARR was developed as a major improvement upon the earlier NCEP/NCAR Global Reanalysis in terms of resolution. NARR provides data at finer spatial and temporal resolutions compared to other the earlier NCEP/NCAR and NCEP/DOE products [16,17]. Air temperature and relative humidity dataset, separated into eight 3-h time periods for each day, are used. The selected historical period spanning 30 years (summer of 1991–2020) allows for a meaningful comparison with the heat observed during the summer of 2023. Near-surface wind speed and pressure from the NCEP NARR³ dataset for the same periods are used in analyzing the atmospheric dynamics associated with the extreme heatwave in the Caribbean. For the sea surface temperature analysis, we used the NOAA's Optimum Interpolated Sea-Surface Temperature (OISST) dataset, version 2.1. This dataset has a 0.25 deg high-resolution optimum interpolation, with a daily and monthly temporal resolution [18,19]. Surface pressure analysis also used ERA5 monthly averaged reanalysis.

The analysis of observed air temperatures for the summer of 2023 reveals a noteworthy climatic scenario, wherein mean maximum temperatures consistently exceeded 90 °F across most coastal areas in Puerto Rico, reaching even higher levels in the US Virgin Islands, as depicted in Fig. 2. Notably, lower biases in temperature were observed in the high elevations. This temperature distribution indicates a pronounced spatial variability, with urban and coastal areas experiencing more intense heat, particularly in lower elevations.

The mean maximum temperatures for summer 2023 are already exceeding the 90 °F threshold in urban and coastal regions, highlighting the intensity of the observed heat, and emphasizing the inherent climatic challenges faced by these areas. Urban areas are particularly vulnerable to heat waves due to the urban heat island (UHI) effect [23]. Coastal areas, influenced by factors like sea surface temperatures and maritime air masses, also tend to experience elevated temperatures. San Juan, Puerto Rico, has a well-documented UHI [24], Velazquez et al. [25].

Before delving into the calculation of heat indices, the observed high temperatures in Fig. 2 indicate an increased potential for heat-related stress and adverse impacts on ecosystems and communities. This preliminary observation sets the stage for a more in-depth analysis of heat indices, which, factoring in humidity, provides a more comprehensive assessment of the perceived temperature and the associated risks of heat-related illnesses.

The historical analysis of heat indices from the ASOS Station data for San Juan and Roosevelt Roads in Puerto Rico provides insights into the historical severity of heat for summer seasons. The findings reveal that the historical mean maximum heat index typically falls within the range of 90 °F–103 °F as shown in Fig. 3, indicating conditions categorized as “extreme caution” on the heat index scale. On average, the perceived temperature during summer in these areas reaches a level that warrants heightened awareness and precautions against heat-related risks. A notable finding of the analysis is that almost 100% of historical summer days recorded a heat index falling between 90 °F and 103 °F, extreme caution (Table 1). This consistency in most days experiencing heat indices within this range highlights the persistent nature of elevated temperatures during summers in San Juan and Roosevelt Roads. Such prolonged exposure to high heat indices, even if not reaching danger levels, still poses health risks and necessitates careful consideration for the well-being of the local population.

A few days within the historical summer exceeded 100 °F heat index. The observation that only a few days within historical summers exceeded a heat index of 100 °F indicates that such extreme conditions are rare but not entirely absent. Ranking of the daily maximum heat index (2000 to 2023) and temperature from 1955 to 2023 revealed that the highest heat index and temperature observed in these two stations are not within 2023 (Table 2). There have been sporadic occurrences of extremely high heat indices, indicating the potential for brief but intense heatwaves during historical summer periods.

The results contribute to a comprehensive understanding of the historical heat conditions in Puerto Rico, providing a baseline for comparison with the specific heatwave observed during the summer of 2023. The prevalence of heat indices within the “extreme caution” range emphasizes the need for proactive measures, public awareness, and adaptive strategies to mitigate the impact of elevated temperatures on the health and safety of the community, particularly during the summer months.

Heat index analysis for the summer of 2023, revealed that both San Juan and Roosevelt roads experienced extreme heat conditions, with the HI frequently surpassing the upper thresholds of the “Extreme Caution” zone and often venturing into the “Danger” zone (Fig. 4). The frequency of days within the “Danger” zone is higher in our findings, suggesting that the summer of 2023 brought particularly harsh conditions to Puerto Rico (Fig. 5). About 70% of the days records heat indices higher than 100 °F in San Juan and Roosevelt Roads, Puerto Rico, with extremes of over 115 °F (46 °C) as shown in Fig. 4. This is indicative of a troubling trend toward more intense and prolonged heat events, which is a part of broader climatic changes affecting the region. The HI's excursions into the “Danger” zone are of greater concern due to the serious health risks they pose, such as heat exhaustion and heatstroke.

The study reveals that although the mean summer maximum temperatures and heat indices in 2023 were higher than the long-term climatology for both San Juan and Roosevelt Roads, these regions have experienced individual years in the past with even more extreme values. Specifically, while the summer of 2023 saw elevated maximum temperatures and heat indices compared to the climatological averages, the historical records show instances where temperatures and heat index values exceeded those observed in 2023. As shown in Table 2, in San Juan, the highest recorded heat index prior to 2023 was 110 °F, surpassing the 109 °F observed in 2023. Similarly, in Roosevelt Roads, past summers have seen heat indices reach up to 122 °F, notably higher than the 118 °F recorded in 2023. This suggests that while 2023 was notably warmer than average, it was not the most extreme year on record, indicating variability in summer thermal extremes over the years.

The comparative analysis of the HI for the summer of 2023 against the historical summer climatology from 1991 to 2020 is extended to the Caribbean region. Our findings reveal a significant rise in HI values, indicative of hotter and potentially more humid conditions than the historical average. Notable is the spread of elevated HI values inland in summer 2023 as shown in Fig. 6. Anomalies above 4 °F prevailed in the Northeastern section of the Caribbean covering Puerto Rico and USVI and extending throughout Hispaniola and Cuba. The significant anomalies can be attributed to a combination of local and regional factors, which are further explored in this study.

The elevated HI values recorded during the summer of 2023 in the Caribbean signify a concerning climatic shift, consistent with global warming trends that predict more frequent and intense heat events. Such anomalies have profound implications, including increased human health risks, particularly heat-related illnesses in vulnerable populations; heightened energy demands with subsequent stress on infrastructure; and potential upticks in greenhouse gas emissions.

Analysis of SST in the region shows remarkably warming SSTs as we progress through the summer months (June, July, and August) as shown in Fig. 7(a). Warming is more prominent off the West Coast of Africa, especially during the months of July and August. Additionally, the warming spreads throughout the MDR (main developing region), an area known for tropical cyclone development located between 10–20 deg N and 20–80 deg W, and the Wider Caribbean area including the Antilles during the later summer months, showing regional spreading in addition to increased warming in the region. Summer SST averages also depict significant increases in warmer SSTs in the summer of 2023 (Fig. 7(b)). Consistent with previous findings from Refs. [19,26], we see continued warming trends in the Caribbean, the surrounding region and the MDR.

The observed increase in SSTs in the Caribbean during the summer months significantly contributed to elevated heat indices. The warming SSTs initiate a cascade of effects, where the ocean surface acts as a primary source of heat for the overlying atmosphere. The warmer ocean waters transfer this heat directly to the air, raising ambient temperatures. Simultaneously, the higher SSTs promote greater evaporation rates. Increased air temperatures lead to the Clausius–Clapeyron effect, where increased temperatures lead to increased vapor pressure. As air temperatures increase, the water-holding capacity of the atmosphere also increases. Therefore, warmer SSTs equals higher evaporation rates, higher evaporation rates equals more atmospheric water vapor, and more atmospheric water vapor leads to more heat trapped in the atmosphere. This increased atmospheric humidity diminishes the effectiveness of evaporative cooling, making it more challenging for the human body to dissipate heat through sweating. As a result, the combination of elevated air temperatures and heightened humidity intensifies the heat index, reflecting the apparent temperature felt by individuals and contributing to more oppressive and uncomfortable conditions in the Caribbean region.

Furthermore, the augmented SSTs play a pivotal role in reinforcing the greenhouse effect. The greater influx of water vapor into the atmosphere augments the atmospheric moisture content and amplifies the trapping of longwave radiation, further warming the lower atmosphere. The positive feedback loop between warming SSTs and heightened air temperatures exacerbates the heat index, creating conditions where the perceived temperature surpasses the actual air temperature.

This result underscores the influence of ocean temperatures on the Caribbean regional climate conditions and highlights the importance of monitoring SST anomalies as indicators of potential heat-related impacts on land.

Our analysis revealed that the mean surface pressure for summer had a pronounced gradient of increasing pressure from the southwest to the northeast, typical of the Northern Hemisphere's summer months. This gradient is influenced by the Azores High, a semi-permanent feature in the North Atlantic that significantly influences the weather patterns over the Caribbean. The mean sea level pressure (SLP) for the baseline period delineates the strength and the position of the Azores High with higher pressures at the Azores.

Contrastingly, the summer of 2023 shows an anomalous sea level pressure pattern. Figure 8 shows a noticeable weakening of the Azores High, with the SLP gradient appearing less pronounced. The shift in SLP distribution suggests a weakening of the high-pressure system, which normally influences oceanic air toward the Caribbean.

This result is consistent with the findings of the Copernicus Climate Change Service. According to The Copernicus Climate Change Service (C3S, 2023), during June 2023, the atmospheric circulation over the North Atlantic basin was unusual. The Azores High was much weaker than average—the weakest in the ERA5 data record for June, by an exceptionally large margin.

The Azores High is instrumental in dictating the strength and direction of the trade winds. The reduced pressure gradient observed in summer 2023 signifies a weakening of the driving force behind atmospheric circulation, leading to diminished wind speeds. This phenomenon has far-reaching implications for the thermal characteristics of the Caribbean region. Weaker winds, resulting from a reduced pressure gradient observed in Fig. 8, facilitate heat accumulation in the atmosphere.

These interconnected processes collectively contribute to the nuanced dynamics of heat distribution in the region, providing valuable insights for a comprehensive understanding of the climatic factors shaping this geographically significant area.

To better understand how the weakened Azores affected the wind patterns, and in turn contributed to extreme heat, analyses of wind speed and direction were made over the Caribbean region (Fig. 9). The near-surface wind speeds during the summer of 2023 are reduced, compared to historical climatology, and have been a contributing factor to the elevated HI experienced in the Caribbean. This phenomenon is due to the weakening of the Azores High, which has resulted in a decreased pressure gradient and weaker trade winds.

The trade winds, when at normal speed, play a significant role in mitigating elevated temperatures by facilitating the transport of cooler air and aiding in the evaporation process, which can have a cooling effect. The observed lower wind speeds caused reduced evaporative cooling and less transport of cooler air from over the ocean to land areas, resulting in higher temperatures and, consequently, higher HI values, particularly in regions where the wind speed reductions are most significant. With reduced horizontal mixing of air masses, there is a prolonged residence time for air in specific areas, allowing for the gradual buildup of heat. This stagnation is particularly impactful in urban areas [26], where heat is absorbed by buildings and pavement, creating urban heat islands. Previous studies by Di Napoli et al. [27] revealed that the increase in heat stress is driven by increases in air temperature and radiation and decreases in wind speed, consistent with our findings.

Our results indicate that there was significant heat stress in major cities such as Miami, Havana, Kingston, Santo Domingo, and San Juan. The densely built environments in these cities exacerbated local temperatures through the urban heat island effect [23]. Given the high population densities in these urban areas, human exposure to extreme heat is considerable. This is supported by our analysis estimating the affected population, which indicates that about 19.2 million of the region's inhabitants were subjected to hazardous heat conditions (Fig. 10), heightening the risk of heat-related illnesses.

This significant rise in the heat index across the Caribbean profoundly affected the educational sector by necessitating widespread school closures and early dismissals to protect students from the dangers of extreme heat. This emphasizes the vulnerability of school-aged children, who are physiologically more susceptible to heat-related illnesses. Children are at increased risk, as their bodies are less able to regulate temperature, and they are more likely to become dehydrated. The lack of adequate infrastructure in schools, such as air conditioning and proper ventilation, compounded the issue, leading to a substantial loss of instructional time and highlighting the urgent need for comprehensive heat action plans.

The high intensity and duration of these heat waves also led to a surge in heat-related illnesses, ranging from mild dehydration and heat exhaustion to more severe cases of heatstroke, a condition that can be fatal if not promptly and properly treated. These conditions are particularly dangerous for the elderly, who are less physiologically able to regulate their body temperature and are more likely to have chronic health conditions that can be worsened by extreme heat [28,29]. For those with preexisting health conditions, such as cardiovascular or respiratory diseases, extreme heat poses a severe risk. The stress on the body caused by high temperatures can trigger acute events, such as myocardial infarction or asthma attacks [30]. The economically disadvantaged people are also disproportionately affected by heatwaves, often due to substandard housing, limited access to air conditioning, and occupational exposure, as many works in outdoor environments [31]. The increased public health risks underscore the imperative for urgent and coordinated action.

In this analysis, we posit that the energy required for maintaining human comfort serves as a primary indicator of the energy demands within buildings. This assumption is particularly significant in contexts where energy consumption from buildings constitutes a substantial portion of the overall energy budget. Notably, in the Caribbean region, where regulating indoor temperatures against the backdrop of inherently hot climates is a critical concern, buildings historically accounted for nearly 50% of the total energy expenditure [20]. Heat index is a better predictor variable for the daily maximum electric power load in summer than the air temperature [23].

As previously detailed, we calculated the energy per capita (in kW) required to sustain a temperature of 22.2 °C, 50% relative humidity, and a ventilation rate of 25.5 m³/h per person. These parameters, aligned with established standards for human comfort and air quality [20–22], were used to assess the energy impact under varying external heat loads. The energy demand was determined using the formula discussed earlier, where the enthalpy difference between the indoor environment and the reference condition indicates the required energy adjustment. This approach enables a precise estimation of how elevated heat index values during heatwaves influence energy consumption in buildings across the Caribbean region.

The historical summer period indicates a relatively lower and uniform energy demand across the Caribbean, with the mean values predominantly between 150 and 175 kWh/month per capita as shown in Fig. 11. Contrastingly, the summer 2023 exhibits a significant escalation in energy demand, as evidenced by the shift toward higher values, particularly in regions such as the Greater Antilles, the Lesser Antilles, and the northern coastline of South America. Notably, countries such as Cuba, Haiti, the Dominican Republic, and Puerto Rico display pronounced increases, indicating per capita energy demands reaching upward of 200 kWh/month. Consistent with our results, according to Ref. [32], the extreme heat in summer 2023 sparked a surge in energy consumption for cooling purposes across the islands.

The anomalies reveal the impact of the summer 2023 heat wave, with values of 15 kWh/month per capita. Notably, areas of higher HI correspond with areas of higher energy demand. We infer that the HVAC (heating, ventilation, and air conditioning) systems operate for extended periods and at higher capacities than usual to maintain the prescribed indoor conditions of 22.2 °C and 50% relative humidity.

We noted a significant increase in the daily peak energy demand across all studied regions during the summer of 2023. For example, in Cuba, the peak demand in buildings frequently exceeded 2500 MW, a 43% increase from the historical average of 1750 MW. Similar trends were observed in other regions: Haiti experienced a 25% increase, the Dominican Republic 20%, Jamaica 15%, and Puerto Rico 30% (Fig. 12(b)). This surge in peak energy demand, primarily for cooling in residential and commercial buildings, reflects the direct impact of higher heat indices. The reliance on air conditioning during the hot summer days results in increased operational demands on the energy grid, necessitating improved grid management and capacity planning. The per capita peak energy demand analysis as shown in Fig. 12(a) depicted a clear pattern of the increased demand concentrated in urban and densely populated areas. Regions with higher population densities face disproportionately higher energy demands, exacerbating the strain on energy infrastructures.

These observations are consistent with broader literature that indicates a global trend toward higher energy demands in response to climate change [33].

The marked increase in peak energy demands for human comfort poses significant challenges to existing building infrastructures, which are not designed to handle such high loads efficiently. Additionally, the increased operational costs due to higher energy consumption impact not only the energy providers but also the end consumers, manifesting as higher utility bills. It is crucial to upgrade building insulation and windows to enhance energy efficiency and reduce cooling costs. Implementing advanced HVAC systems that can manage increased demands more efficiently and cost-effectively is also essential [34].

The heightened demand for energy did not only place considerable strain on power grids but also led to outages and blackouts. The reliance on electricity for cooling and ventilation means that power outages during these periods of intense heat left individuals without the means to mitigate the sweltering conditions, significantly increasing the risk of heat-related illnesses. The authors acknowledge that the infrastructure and capacity to meet these escalating energy demands are not uniformly available across all the countries in the region, which exacerbates the challenges associated with managing the impacts of extreme heat events.

We conducted a comparative analysis of the daytime and nighttime UHI for San Juan by comparing the maximum and minimum temperatures between San Juan, urban environment, and Palmarejo in Vega Baja, representing a rural setting [25]. Palmarejo, situated approximately 28 miles west of San Juan and located inland, was selected to avoid significant coastal influences, and to provide a natural temperature baseline, ensuring a distinct contrast to the urban heat excess observed in San Juan. The UHI for San Juan has been widely reported in Refs. [24,35,36] and Velazquez-Lozada et al. [25]. Our new analysis reveals a pronounced UHI effect in San Juan compared to the rural baseline in Palmarejo, with a mean UHI_max of 3.82 °F and an even more substantial UHI_min of 9.42 °F. The significant nighttime temperature difference underscores the urban environment's propensity to retain and slowly release heat absorbed by buildings, roads, and other infrastructure throughout the day [24]. This reduced capacity for nighttime cooling in the city exacerbates heat stress during heatwaves by prolonging exposure to elevated temperatures, demonstrating that the UHI in San Juan not only intensifies daytime heat but also critically extends the duration of heat exposure into the night, significantly increasing the thermal burden on the urban population. The bottom panels in Fig. 13 offer a historical perspective, revealing that the average daytime UHI_max for the period 2000–2020 was 2.50 °F, and the nighttime UHI_min averaged 7.42 °F. The comparison between the 2023 and historical UHI shows that the UHI effect was intense in summer 2023. This intensification is directly connected to the overall higher temperatures observed during the summer of 2023, as discussed in the broader context of this study. The UHI effect also increased energy consumption in major cities, particularly during summer 2023 heat, placing additional stress on the power grid.

This study has undertaken a comprehensive analysis of the extraordinary extreme heatwave that unfolded in the Caribbean during the summer of 2023. The study attempts to contribute to our understanding of extreme heat events in Puerto Rico, USVI, and the larger Caribbean region and their broader implications in the context of climate change. These findings not only highlight the localized heatwaves on Puerto Rico but also emphasize a pervasive regional pattern, with consistently elevated heat indices throughout the Caribbean. As extreme heat events become more prevalent, our study serves as a call to action for regional and global collaboration to address the complex challenges posed by climate change. The implications extend beyond immediate concerns for human populations, encompassing the vulnerability of ecosystems and the imperative to develop sustainable solutions.

A future marked by increasing Caribbean temperatures makes it worse, and so, this research contributes to the ongoing dialogue on sustainable practices and resilience-building measures essential for the continued safety of the Caribbean in the context of extreme heat events. The development and implementation of sustainable practices, along with the bolstering of community resilience, emerge as critical pathways to safeguard the future of the Caribbean. To mitigate the impacts of extreme heat events in the Caribbean, a multifaceted approach is essential. Enhancing the density and capabilities of meteorological infrastructure will improve data collection and forecasting, allowing for better-prepared communities and more effective response strategies.

Building upon the insights gleaned from this study on the extreme heatwave experienced in the Caribbean during the summer of 2023, it is imperative to formulate practical and effective adaptive strategies and mitigation measures to safeguard vulnerable communities and ecosystems. First, community-based early warning systems should be established to provide timely alerts and guidance, allowing residents to take necessary precautions during periods of extreme heat. Implementing urban planning strategies that incorporate green spaces and cool roofs can mitigate the urban heat island effect, offering localized relief. Public health campaigns should educate communities on the risks of heat-related illnesses and promote hydration and proper heat-protective measures. Additionally, targeted infrastructure improvements, such as resilient energy systems and enhanced cooling facilities, can bolster the region's ability to withstand extreme heat. Collaboration between governments, Non-Governmental Organizations, and local communities is crucial to ensure the practical implementation of these measures, emphasizing adaptability to the specific needs and contexts of each community in the Caribbean. By integrating these practical strategies, we can enhance resilience and foster sustainable development in the face of escalating climate challenges.

A comprehensive investigation into the persistent decrease in wind speed during the same period is essential for a more holistic understanding of extreme heat events. Further studies could explore the interconnectedness between atmospheric circulation patterns, reduced pressure gradients, wind speed, and their role in influencing the Caribbean Climate. Integrating advanced climate modeling techniques and considering long-term trends will enhance the accuracy of future predictions regarding the frequency and intensity of extreme heat events in the Caribbean. Moreover, exploring the socioeconomic and ecological impacts of prolonged heatwaves on vulnerable communities and ecosystems will contribute to the development of effective adaptive strategies and mitigation measures tailored to the region's specific needs.

We extend our heartfelt gratitude to the University at Albany Atmospheric Science Research Center, The Coastal Urban Environmental Research Group, and the Caribbean Climate Adaptation Network (CCAN), a NOAA CAP/RISA team, for their invaluable support throughout the course of this research. Their expertise, resources, and guidance have been instrumental in the development and completion of this study. Special thanks to the National Oceanic and Atmospheric Administration (NOAA) for financially supporting this work (Grant No. NA22OAR4310545). This funding has greatly helped advance knowledge in extreme weather and climate over the Caribbean.

This work was also supported (in part) through the NOAA Educational Partnership Program/Minority-Serving Institutions award NA22SEC4810016 Center for Earth System Sciences and Remote Sensing Technologies II. Contents are solely the responsibility of the author(s) and do not represent official views of NOAA or the U.S. Department of Commerce.

There are no conflicts of interest.

The datasets generated and supporting the findings of this article are obtainable from the corresponding author upon reasonable request.