Weather in Rio de Janeiro in August

Prime time. If you get to pick your dates, August is the one. Highs average 25.7 °C, lows 18.9 °C, and rain falls on 7 days — nothing in the month is working against you.

August ranks 3 of 12 in Rio de Janeiro. Only July scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 7 days, 1 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest August day reached 36.3 °C and the coldest night fell to 15.1 °C, and the wettest single day dropped 52 mm — roughly 124% of the month's rain in one day.

This is the volatile part. August rainfall has ranged from 11 mm to 162 mm across the twenty years measured — a 151 mm spread around an average of 42 mm. The average is real but almost no individual August looks like it, so treat the figure as the middle of a wide range rather than a forecast.

Wind is light at 10.7 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 77%, high enough to notice on the warm days without dominating them.

How August sits in the year

Temperatures hold steady either side: 25 °C in July, 25.7 here, 26.4 in September. Nothing about the timing within the month matters much.

Daylight in August

11.3 hours of daylight, gaining 0.5 hours across the month. That is between Rio de Janeiro's extremes of 13.5 and 10.7 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 22.4 °C in August — comfortable for a proper swim. The sea peaks at 26.7 °C in March and bottoms out at 22.3 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead. If the dates are flexible, October is the trade worth considering — 14 points weaker on weather, and materially quieter.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

August in Rio de Janeiro versus nearby

If Rio de Janeiro is one option among several, the nearby comparison is worth making. Belo Horizonte is close enough to be a coin toss — 2.2 °C warmer, 4 days less rain. São Paulo is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: August is effectively as good as it gets here — 2 points behind July, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Rio de Janeiro

See all twelve months in Rio de Janeiro, or where else to go in August.