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Brazil's Climate
Climate / Weather in Brazil
Although 90 percent of the country is within the tropical zone,
the climate of Brazil 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, averaging above 25°C,
but not reaching the summer extremes of up to 40°C in the temperate
zones. There is little seasonal variation near the equator, although
at times it can get cool enough for wearing a jacket, especially
in the rain. At the country's other extreme, there are frosts south
of the Tropic of Capricorn during the winter (June-August), and
in some years there is snow in the mountainous areas, such as Rio
Grande do Sul and Santa Catarina. Temperatures in the cities
of São
Paulo, Belo
Horizonte, and Brasília are moderate (usually between
15°C and 30°C), despite their relatively low latitude, because
of their elevation of approximately 1,000 meters. Rio
de Janeiro, Recife, and Salvador
on the coast have warm climates, with average temperatures ranging
from 23°C to 27°C, but enjoy constant trade winds. The southern
cities of Porto Alegre and Curitiba have a subtropical climate similar
to that in parts of the United
States and Europe,
and temperatures can fall below freezing in winter.
Precipitation levels vary widely. Most of Brazil has moderate rainfall
of between 1,000 and 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 more than 2,000 millimeters per year and reaching as high
as 3,000 millimeters in parts of the western Amazon and near Belém.
It is less widely known that, 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.
High and relatively regular levels of precipitation in the Amazon
contrast sharply with the dryness of the semiarid Northeast, where
rainfall is scarce and there are severe droughts in cycles averaging
seven years. The Northeast is the driest part of the country. The
region also constitutes the hottest part of Brazil, where during
the dry season between May and November, temperatures of more than
38°C have been recorded. However, the sertão , a region
of semidesert vegetation used primarily for low-density ranching,
turns green when there is rain. Most of the Center-West has 1,500
to 2,000 millimeters of rain per year, with a pronounced dry season
in the middle of the year, while the South and most of the Atlantic
coast as far north as Salvador,
Bahia, in the Northeast, have similar amounts of rainfall without
a distinct dry season.
Geographic Regions
Brazil's twenty-six states and the Federal District (Distrito Federal)
are divided conventionally into five regions--North
(Norte), Northeast, Southeast
(Sudeste), South, and Center-West
(see fig. 4). In 1996 there were 5,581 municipalities (municípios
), which have municipal governments. Many municipalities, which
are comparable to United States counties, are in turn divided into
districts (distritos ), which do not have political or administrative
autonomy. In 1995 there were 9,274 districts. All municipal and
district seats, regardless of size, are considered officially to
be urban. For purely statistical purposes, the municipalities were
grouped in 1990 into 559 micro-regions, which in turn constituted
136 meso-regions. This grouping modified the previous micro-regional
division established in 1968, a division that was used to present
census data for 1970, 1975, 1980, and 1985.
Each of the five major regions has a distinct ecosystem. Administrative
boundaries do not necessarily coincide with ecological boundaries,
however. In addition to differences in physical environment, patterns
of economic activity and population settlement vary widely among
the regions. The principal ecological characteristics of each of
the five major regions, as well as their principal socioeconomic
and demographic features, are summarized below.
Data as of April 1997
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