Brazil - weather in December

December in Brazil is the first month of summer in the center-south, while in the center-north, where it is hot all year round, we cannot properly speak of seasons, except as regards the rains. Almost everywhere, December is a hot, muggy and rainy month, except in the far north, in the state of Roraima (see Boa Vista), where we are in the dry season. The rains are abundant in the vast Amazon basin (although it usually increases further in January and February) and in some southern areas (see Brasíla), where this is often the rainiest month of the year. Instead, it is still the dry season in the eastern part of the north coast (see Parnaíba, Fortaleza, the archipelago of Fernando De Noronha) and the easternmost part (see Natal, Joao Pessoa, Recife, Maceió, Aracaju).
At sea level, the average temperature is 29 °C (84 °F) in the extreme north (see Boa Vista), 29/30 °C (84/86 °F) in the Sertão, the hot and arid area of the northeast (see Teresina), is about 28 °C (82.5 °F) in the Amazon forest on the north-eastern coast (see Fortaleza), is 26.5 °C (80 °F) in Rio De Janeiro, 25 °C (77 °F) in the south (see Florianópolis, Porto Alegre) and 23 °C (73.5 °F) in the southern tip (see Rio Grande).
Even though the average temperatures are lower, in the center-south it is more probable that there are heat waves, during which the temperature can reach 38/40 °C (100/104 °F).
However, sometimes cool air can arrive in the south, so that the night temperature can drop below 15 °C (59 °F) and below 10 °C (50 °F) in cities located at hilly altitudes.
The sea is warm enough for swimming almost everywhere, while in the extreme south (see Porto Alegre, Rio Grande), the sea is still a bit cool, and the water temperature drops below 23 °C (73.5 °F).
While in the north, crossed by the Equator, the day lasts 12 hours all year round, in the center-south, December and January are the months in which the days are longest, and last up to 14 hours in the extreme south.




See also: Brazil, the weather in November - January
The climate of Brazil