The climate of the region is influenced by many factors, and the most significant is the latitude. The reason for this is that different latitudes receive a different amount of solar energy. For example, locations with lower latitudes near the equator receive more sun energy than locations with high latitude farther than the equator. Rain, humidity and wind can be more or less at all latitudes, but the solar energy gradually decreases from low to higher latitudes, so that at distant locations from the equator, this amount is drastically reduced.
The answer is sun.