Weather in Rio de Janeiro in August

How August compares

August is the 9th warmest month of the year in Rio de Janeiro and ranks 120th of 134 destinations we compare for August - see where else is hot in August. Against London's average high of 21.4°C in August, Rio de Janeiro is 4.3°C warmer by day and 4.1°C warmer at night.

Daytime and night-time in August

The typical August day in Rio de Janeiro peaks at 25.7°C, but that is an average: the warmest 10% of days reach 30.6°C or more. About 57% of days top 25°C and 1 in 7 pass 30°C. Nights average 17.6°C; one night in ten drops to 15.4°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest August day here reached 35.4°C (1993-08-31) and the coldest night 11.8°C (2011-08-05).

Rain in August

Some rain (4-8 rainy days): about 8 days with 1 mm or more, 44 mm in total. Year to year it varies a lot - the wettest August was 2003 with 107 mm, the driest 2005 with 14 mm. Humidity averages 78%.

Sea temperature in August

The sea averages 21.7°C - bracing (18-22°c). Depending on the year it ranges from 20.8°C to 22.5°C. For the warmest sea here, come in February (26.4°C).

Sunshine and daylight

Around 6.2 hours of sunshine a day (estimated from cloud cover), 11.2 hours of daylight: the sun rises about 06:18 and sets about 17:37 local time in mid-August. Average cloud cover is 44%.

Is August a good time to visit Rio de Janeiro?

Yes - it is one of the better months: hot days, manageable rain. The best months for Rio de Janeiro on our scoring are August, June, July; months averaging 25°C or more: Jan, Feb, Mar, Apr, May, Jun, Aug, Sep, Oct, Nov, Dec.

Warm days, with room for hotter spells

Pack mainly for warm weather, but leave space for cooler evenings. Days reach 25°C on 57% of the month, so summery conditions are common rather than guaranteed. Heat can still build: 13% of days reach 30°C, making shade and a slower pace sensible around midday when it is hot. Loose clothing and sun protection will be useful, while a jumper or light jacket should cover many evenings. The coldest 10% of nights fall to 15.4°C or below, so packing only beachwear would be a mistake. August suits travellers who enjoy warmth but do not need every day to feel hot.

Some rain, but useful sunshine

Expect some interruptions from rain rather than planning on an entirely dry holiday. August has about 8 rainy days, so a light waterproof and flexible outdoor plans are sensible. That does not mean writing off each wet day, but it does mean avoiding a schedule that depends on clear skies throughout. Average sunshine is about 6.2 hours within 11.2 hours of daylight, leaving a useful window for outdoor time without promising constant sun. Humidity averages 78%, which can make warmer spells feel sticky. Choose breathable clothes, allow time to cool down, and keep an indoor alternative in mind when rain threatens.

Better for beach time than lingering in the sea

The sea is the main compromise if swimming is your priority. At an average of 21.7°C, it falls in the bracing range, so getting in may take some resolve even when the air feels warm. The year-to-year range of 21°C to 22°C gives little reason to expect a much warmer sea. Plan around enjoying time by the water, with swims depending on your tolerance, rather than assuming you will want to stay in for ages. A towel and a dry layer are useful afterwards, particularly as the day cools. August is a better fit for mixing beach time with walking than for a holiday focused entirely on swimming.