In this paper, thermal modeling of hybrid PV/T system has been developed under combined (front and back) water surface cooling. An analytical expression has been derived for solar cell temperature (Tcs), back surface temperature (Tbs) and overall efficiency (ηOE) of hybrid PV/T system for winter condition. Statistical analysis have been performed in the cold climate of MNIT, Jaipur (India) for determining performance parameters of the hybrid PV/T system. An experimental validation has been carried out for the developed thermal model and observed the fair agreement between the numerical and experimental observations. We have also calculated the electrical (ηele), thermal (ηth)and overall efficiency (ηOE) and found the 18.83%, 43.8% and 64.56%, respectively and output power 57.39 mW in winter condition. We have also noticed that 1.5 LPM gives the better performance out of four (1, 1.5, 2, and 2.5 LPM) flow rates.