Weather in Rio de Janeiro

On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are June, July, and August. Rio de Janeiro is in Brazil at 22.9°S. The 2001–2020 NASA POWER daily record describes a monsoon climate with a sharp wet-dry split.

February is the warmest month (average 26.2°C, high 28.8°C) and July is the coolest (average 21.4°C, low 18.3°C). Rain is the monsoon runs from October to April, inside an annual total of 1469 mm. The wettest month is December at 232 mm; the driest is August at 42 mm.

Rainfall pattern

The monsoon in Rio de Janeiro starts in October and ends in April (October, November, December, January, February, March, and April). December is the core of it at 232 mm. August is the other extreme, with 42 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. December averages 20 such days; August averages 7.

Temperature through the year

Rio de Janeiro has a 4.8°C gap between its coolest monthly average (21.4°C in July) and its warmest (26.2°C in February). That is a southern-hemisphere pattern.

Mean high across all twelve months is 26.6°C and mean low is 21.0°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

Distinctive months in Rio de Janeiro

Peak heat arrives in February: 28.8°C by day, 23.6°C at night, and 83% humidity. By April the monsoon is ending. Rio de Janeiro still sees about 101 mm, but the next month is usually leaner. July is the coolest month, with lows around 18.3°C and highs near 24.5°C. Rainfall is 45 mm.

August is the driest month, averaging only 42 mm across 7 rainy days. Highs sit near 25.2°C. November brings 220 mm and 20 rainy days; temperatures run from 21.2°C to 26.5°C. December is the wettest month — 232 mm and 20 rainy days, with 84% humidity.

Best months to visit Rio de Janeiro

The three months with the highest comfort score are June, July, and August: June (21.9°C average, 49 mm, 80% humidity); July (21.4°C average, 45 mm, 78% humidity); August (21.8°C average, 42 mm, 77% humidity). They fall in calendar order. The score rewards averages near 22°C, lower rainfall, and humidity near 60%. It is a climate score, not a festival or price calendar.

If you want the monsoon itself — fewer crowds, greener landscape, heavier rain — aim at October–April instead of the score.

How Rio de Janeiro compares inside Brazil

Belo Horizonte is about 341 km away: Rio de Janeiro is 3.3°C warmer than Belo Horizonte in its hottest month and 259 mm wetter over the year than Belo Horizonte. Belo Horizonte’s wettest month is December (266 mm) versus December here.

Guarulhos is about 348 km away: Rio de Janeiro is 2.8°C warmer than Guarulhos in its hottest month and 90 mm wetter over the year than Guarulhos. Guarulhos’s wettest month is January (228 mm) versus December here.

São Paulo is about 360 km away: Rio de Janeiro is 3.3°C warmer than São Paulo in its hottest month and 117 mm wetter over the year than São Paulo. São Paulo’s wettest month is January (230 mm) versus December here.