Located in the tropics (nearest the equator), tropical climates have year-round high temperatures at low elevations, and average temperatures of 18° C (64° F) or higher. Of the three below, we’ll most often use the tropical rainforest climate, as the differences between the others are too subtle to matter to most of us; they amount to less uniform rainfall throughout the year.
In this climate, each month has average rainfall of 60 mm (2.4 in), and this climate is usually found within 5-10° of the equator but can sometimes extend up to 25° away. There is little seasonal change here, because the temperatures stay the same year-round, as do the number of daylight hours (changes are small). Many places are uniformly wet unless a rain shadow causes less rain there. Land at a higher altitude will have a milder climate and, due to a rain shadow, might even be relatively dry. Assign this climate to most areas near the equator, such as Brazil and Peru.
This climate is rare enough that we may want to ignore it during world building. Monsoon winds are those that change direction with the season and last several months. These winds cause this climate, which has a driest month just after the winter solstice. The wet season is months long. Some areas alternate between being arid, like a desert, to lush with green vegetation in the wet season, the stark contrast happening within weeks. The trade winds can bring enough moisture to cause rain in the winter months, preventing an area from having our next climate. Miami has this climate.
Tropical Wet/Dry or Savannah
This climate has a more pronounced dry season of very little rain and is usually in the outer edges of the tropical region, farther from the equator. Some of the wettest places on Earth have this climate, with incredible rainfalls during the wet season, sometimes in a single day. Examples include areas of Africa, Brazil, and India.