The purpose of this study is to characterize the thermal response of assembled propellant increments exposed to a variety of thermal environments and packaging conditions. The temperature distribution and bulk temperature of the propellant within the increment directly influence the burn rate and resulting pressure profile. The burn rate and pressure profile directly impact the range and stability of the munition which can result in a safety hazard if not properly accounted for. In this study first a numerical model is developed and then this numerical model is used to make a determination of whether a surface temperature measure or series of surface temperature measurements can be used to approximate or estimate the bulk propellant temperature. The numerical model accounts for variable thermal solar loading, various packaging configurations, and orientation. The results indicate that the temperature response of the assembly is influenced by both configuration and assembly. The increment notch orientation also has a significant impact on results. Orientation of the increment can also affect the maximum temperature response and care should be given to determine the heating conditions if the highest temperature exposure needs to be identified. Natural convection is relatively weak and both the small cavity size and slow temperature change drive this condition.