Tropical humid climates (A)

Group A, tropical humid climates, lie between the Tropics of Cancer and Capricorn. The sun is overhead during the year and the ITCZ is present, so they are hot and humid, with a very low annual range of temperature and high rainfall. Three types:

• Af, tropical wet: near the equator: the Amazon Basin, western equatorial Africa, the islands of the East Indies. Rain in every month, often as afternoon thundershowers. Temperature is uniformly high: about 30°C by day and 20°C at night, with a negligible annual range. Tropical evergreen forests with a dense canopy and great biodiversity.
• Am, tropical monsoon: the Indian sub-continent, north-east South America, northern Australia. Heavy rain mostly in summer; dry winter.
• Aw, tropical wet and dry: north and south of Af regions, bordering dry climates on the west of continents and Cf or Cw on the east. Large areas north and south of the Amazon forest in Brazil, parts of Bolivia and Paraguay, Sudan and south of Central Africa. Rainfall is less than in Af and Am and variable; the wet season is shorter and the dry season longer, with more severe drought. Daily temperature range is greatest in the dry season. Deciduous forest and grassland with scattered trees.

Example (new): Kerala's coast, with very heavy rain from June to September and a dry spell in winter, fits Am; a savanna in East Africa with a few months of rain and a long dry season fits Aw.