Brazil's climate has little seasonal variation since most of the country is located within the tropics. However, although 90% of the country is located within the tropical zone, year-long climate varies considerably from the mostly tropical North (the equator traverses the mouth of the Amazon) to temperate zones below the Tropic of Capricorn (23°27' S latitude), which crosses the country at the latitude of the city of São Paulo. Brazil has five climatic regions: equatorial, tropical, semiarid, highland tropical, and subtropical.
Temperatures along the equator are high, with averages above 25 °C (77 °F), and occasionally reaching the summer extremes of up to 40 °C (104 °F) in the temperate zones. Southern Brazil has a subtropical temperate weather, normally experiencing frost in the winter (June-August), and snowfall in the mountainous areas, such as Rio Grande do Sul and Santa Catarina. Precipitation levels vary widely. They are higher in the humid Amazon Basin, and lower in the somewhat arid landscapes of the northeast. Most of Brazil has moderate rainfall of 1,000 to 1,500 millimeters a year, with most of the rain falling in the summer (between December and April), south of the Equator. The Amazon region is notoriously humid, with rainfall generally of more than 2,000 millimeters per year, getting as high as 3,000 millimeters in parts of the western Amazon and near Belém. Despite high annual precipitation, the Amazon rain forest has a three-to-five-month dry season, the timing of which varies according to location north or south of the equator.