This study developed a numerical model to simulate a continuous hybrid microwave heating process using a single-mode microwave resonant cavity. A hybrid heating process combines the volumetric energy deposition from microwaves with a convective heat flux at the surface. This combination of heating mechanisms may be used to produce more uniform temperature distributions than either method alone. A Finite Difference Time Domain (FDTD) technique was used to model the electric field distribution. The field strength data allowed power deposition to be approximated and the control volume method was used to solve the energy equation. Temperature dependence of dielectric properties was simulated through an iterative process. This simulation showed that hybrid heating schemes can be used to increase uniformity of the temperature distribution and reduce incidences of thermal runaway.