Systems and methods are described herein for determining an optimized flight route for an aerial vehicle. In some examples, weather conditions for the aerial vehicle during a flight can be predicted based on weather data. At least two flight route segments based on the predicted weather data can be determined. The at least two flight route segments can include one of a solar flight route segment and a thermal flight route segment. A respective flight route segment of the at least two flight route segments can be discarded that can cause the aerial vehicle to violate a flight constraint. A replacement flight route segment for the respective discarded flight route segment can be determined. An optimized flight route for the aerial vehicle can be generated based on the replacement flight route segment and at least one remaining flight route segment of the at least two flight route segments.