Short answers, pulled from the story.
The tropical climate group is designated by the letter A in the Köppen classification system. It encompasses areas below 23.5 degrees latitude in both the northern and southern hemispheres. This group is defined by a strict thermal rule where the mean temperature of the coldest month must be greater than or equal to 18 degrees Celsius.
Wladimir Köppen drew his first climate map after the 1st of January 1900 marked the beginning of a systematic global effort to categorize the Earth's weather. The concept of the tropical climate had been observed by ancient mariners for millennia before this date. The German botanist established the framework for understanding the world's most biodiverse regions after this time.
The tropical rainforest climate designated as Zone Af receives over 100 inches of precipitation annually. This climate is found within just 5 to 10 degrees of latitude from the equator. The annual precipitation ensures that drought is a concept that rarely exists in these regions.
The tropical monsoon climate labeled Am exists between 10 degrees north latitude and the Tropic of Cancer. This climate is found in South and Southeast Asia, West Africa, and parts of South America. The annual average temperature remains stable around 18 degrees Celsius in these specific locations.
In the tropical wet and dry or savanna climate the driest month precipitation known as Pdry is less than 60 millimeters. This threshold creates a pronounced dry season that shapes the landscape and the lives of its inhabitants. The driest months typically in the winter receive less than 60 millimeters of rainfall.