Short answers, pulled from the story.
Wladimir Köppen published his first climate classification system in 1884. He designed the method to categorize global weather patterns based on temperature and precipitation data collected from meteorological stations worldwide.
A region qualifies as tropical if its coolest month stays above 18 degrees Celsius year-round. This threshold distinguishes these regions from dry B-group climates or temperate zones with colder winters.
The upper Amazon basin of South America hosts some of the largest continuous tropical rainforests on Earth. Rainfall here reaches over 100 inches annually with no distinct dry season.
Regions between 10 degrees north latitude and the Tropic of Cancer experience heavy monsoon rains during summer. A short dry season occurs almost always in the winter months when winds reverse direction.
Rhodes grass and red oats grass dominate the open landscapes of central Africa and northern Australia. These flat grassland vegetation cover nearly 20 percent of Earth's land surface in these regions.