When thinking about the best time to visit Brazil, it's worth bearing in mind that the country splits into four distinct climatic regions. The coldest part – in fact the only part of Brazil that ever gets really cold – is the South and Southeast, the region roughly from central Minas Gerais to Rio Grande do Sul that includes Belo Horizonte, São Paulo and Porto Alegre. Here, there’s a distinct winter between June and September, with occasional cold, wind and rain. Although Brazilians complain, it’s all fairly mild to anyone coming from the US or UK. Temperatures rarely hit freezing overnight, and when they do it’s featured on the TV news. The coldest part is the interior of Rio Grande do Sul, in the extreme south of the country, but even here there are many warm, bright days in winter, and the summer (Dec–March) is hot. Only in Santa Catarina’s central highlands does it (very occasionally) snow.
The coastal climate is exceptionally good. Brazil has been called a “crab civilization” because most of its population lives on or near the coast – and with good reason. Seven thousand kilometres of coastline, from Paraná to near the equator, bask under a warm tropical climate. There is a “winter”, when there are cloudy days and sometimes the temperature dips below 25°C (77°F), and a rainy season, when tropical downpours are severe enough to kill dozens every year in flash floods and landslides. In Rio and points south, the rains last from October through to January, but they come much earlier in the Northeast, lasting about three months from April in Fortaleza and Salvador, and from May in Recife. Even in winter or the rainy season, the weather will be sunny much of the time, with rain usually falling in intense but short bursts.
The Northeast is too hot to have a winter. Nowhere is the average monthly temperature below 25°C (77°F) and the interior, semi-arid at the best of times, often soars beyond that – regularly to as much as 40°C (104°F). Rain is sparse and irregular, although violent. Amazônia is stereotyped as steamy jungle with constant rainfall, but much of the region has a distinct dry season – apparently getting longer every year in the most deforested areas. Belém is closest to the image of a humid tropical city: it rains there an awful lot from January to May, and merely quite a lot for the rest of the year. Manaus and central Amazônia, in contrast, have a marked dry season from July to October.