The weather in Rio de Janeiro is a bit different than most people think, it actually rains quite a lot; obvious proof of that is how Atlantic rainforest grows all over the city. Don’t get me wrong, it’s not like Scotland; even though it rains it is seldom for more than a few days but when you hear the words frente frio (English: cold front) prepare yourself for a few days of rain. You get bright sunny days almost every week.
Other Pages – Climate in Brazil and Waves
First I’d like to introduce two other of my pages that might have the information you are looking for. The first is Climate in Brazil where you will find Brazil forecasts as well as some climate background for this country. For general surf conditions and waves in Rio just go to Rio Surf Report.
Weather in Rio Averages – Rain, Temperature and Sun Hours
In general you can say that the wetter months are Dec, Jan, Feb and March; you can get up to 140mm of rainfall any of these months. The drier ones are Jun, Jul, Aug and Sep when you get as little as 40mm per month. Temperatures are during Dec, Jan, Feb and Mar around 26 degrees Celsius; Jun, Jul and Aug it’s around 20. The average of sun hours is harder to predict, on average you get 150 per month. Note that the west of the state (Ilha Grande, Paraty and Trindade) gets more rain and less sun than the east (Búzios, Cabo Frio and Arraial do Cabo); Rio de Janeiro is somewhere in the middle. In the mountains it’s (for obvious reasons) a bit colder.