Why does it rain so much in the tropical rainforest?

The proximity to the equator, which results in higher temperatures and more water available, contributes to some of the rainfall; however, it is actually the rain that causes the rainforests, not the other way around.

Because there are so many plants in tropical rainforests, there is a lot of transpiration—all plants take in water through their roots, which then travels through their system and out through their leaves, or leaf equivalents—and when that much water vapor is hovering over rainforests, it is inevitable that a lot of rain will fall.

The phenomenon can be seen in action as the Amazon is being cleared for development; the areas being cleared experience a reduction in humidity and rainfall.

In conclusion, tropical rainforests are limited to regions with heavy rainfall and increase precipitation through transpiration.

The high amount of rainfall in tropical rainforests is primarily due to the warm temperatures, abundant sunlight, and high humidity, leading to continuous evaporation and condensation cycles that result in frequent and heavy rainfall.