The best months for travel to Brazil...
There is no exclusive seasonal time to avoid when travelling to Brazil. If your visit does not have to coincide with Carnival in February, then you are best off avoiding the high season and heat of the months of December to March when the country fills with the largest numbers of foreign visitors and locals on their vacation. Low season runs from May to September (except for July which is a school holiday month).
Rio de Janeiro & The Southern Coast
The South and South East have more temperature variations, dropping to 15C in winter (June to August) and rising as high as 35C in the height of Summer. You can expect some rain spells from October to January. Humidity is a fact of everyday life and levels can go as far as 98%!
This area is characterised by a rainy season December to May. For trekking in the Amazon, the best climatic conditions are found between April and November when it is drier and less hot. Summer temperatures in Amazonia rise to high 30s C being more temperate the rest of the year (early to mid 20s C) although you can’t avoid humid conditions. Wildlife spotting is easier during the driest period of the year when the rivers retreat into their main flow.
The Pantanal can get especially hot in rainy season (up to low 40sC or 100F) during December to March whilst the driest and more pleasant time to go is May to October. During the wetter months the area is characterised by flooding and rain which can make it more difficult to get around (avoid February and March if possible) when the heaviest rain falls cause havoc with the roads. Jaguar spotting is recommended from May through until September, during the driest months of the year. For bird watchers, the best time to venture out is June to September.
Salvador de Bahia
All of the Northeast is warm year-round and benefits from nice breezes from the ocean. You can expect temperatures of around 20-30C or 80-90F throughout the year but the hottest and most humid months are October to March during the Brazilian summer. Between June and July in winter time, there is some rainfall but sunshine always returns!
No celebration can top the exuberance and spirit of Carnival (Friday to Tuesday preceding Ash Wednesday), which takes precedence in Rio and Salvador primarily, although the whole country gets in party mode. The epitome of the celebrations is in the Sambadrome, a purpose built space where huge crowds gather to admire float parades with dancers, drumming and singers to the samba beat. If you are in Salvador da Bahia on the second Thursday of January, you can also witness the famous Candomblé festival (Washing of Bonfim church).