The concept of four separate seasons (winter, spring, summer, and fall) is exclusive to the temperate regions. As you go nearer to the polar regions, winter grows longer and longer, summer disappears, and spring and fall merge into one shortened period until you get one season all year round - extreme cold.
Similarly, as one approaches the tropics, winter disappears, and fall and spring merge into one long, slightly cooler season. In the tropics, there are but two types of weather - the hot season and the rainy season.
These aren't true seasons - while April, May, June and July are the height of the summer (in the Northern hemisphere) there are still days of occasional (and welcome) rain. Similarly, while October, Novemember and December is the rainy season, it is still extremely hot. Most people just call it the monsoon season since the rains come with the shifting of the trade winds and the arrival of the typhoons.