Climate averages 1991–2020
Rio de Janeiro weather
in August.
A warm, moderately wet month: the 9th warmest and the driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
August is a warm month in Rio de Janeiro: daytime highs average 25.9°C and nights cool to about 17.5°C. By daytime temperature it is the 9th warmest of the 12 months.
Expect about 41 mm of rain on roughly 8 days, which makes August a moderately wet month (the driest month of the year). Daylight, from sunrise to sunset, lasts about 11 h 20 min on an average August day.
The nearest other city in this atlas is São Gonçalo (16 km away). In August its highs average 25.3°C, 0.6°C cooler than Rio de Janeiro, with 44 mm of rain.
Among the 448 cities listed in Brazil, Rio de Janeiro ranks joint 218th of 448 for the warmest August highs and joint 270th of 448 for the driest August (rainfall, lowest first). The mean August high of those 448 cities is 26.2°C; Rio de Janeiro is 0.3°C cooler than that mean.
From August to September, average highs rise by 1.0°C to 26.8°C, and monthly rainfall rises from 41 mm to 75 mm.
The annual picture
August in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Rio de Janeiro climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 30.7°C23.5°C | 23.5°C | 170 | 16.4 | 13.413 h |
| February | 31.2°C23.6°C | 23.6°C | 118 | 13.3 | 12.913 h |
| March | 29.6°C23.0°C | 23.0°C | 145 | 16.7 | 12.212 h |
| April | 28.0°C21.4°C | 21.4°C | 88 | 12.0 | 11.612 h |
| May | 25.6°C19.0°C | 19.0°C | 76 | 11.1 | 11.011 h |
| June | 25.2°C17.8°C | 17.8°C | 48 | 7.3 | 10.811 h |
| July | 24.9°C17.1°C | 17.1°C | 51 | 7.9 | 10.911 h |
| August, selected | 25.9°C17.5°C | 17.5°C | 41 | 7.5 | 11.311 h |
| September | 26.8°C18.6°C | 18.6°C | 75 | 10.5 | 11.912 h |
| October | 28.0°C20.0°C | 20.0°C | 92 | 11.7 | 12.613 h |
| November | 28.0°C21.0°C | 21.0°C | 139 | 15.8 | 13.213 h |
| December | 29.7°C22.6°C | 22.6°C | 151 | 16.2 | 13.514 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- São Gonçalo in AugustBrazil · 16 kmHigh 25.3°C · Low 16.8°C · 44 mm rain
- Duque de Caxias in AugustBrazil · 19 kmHigh 26.1°C · Low 16.7°C · 44 mm rain
- Barra da Tijuca in AugustBrazil · 21 kmHigh 26.5°C · Low 17.5°C · 41 mm rain
- Belford Roxo in AugustBrazil · 27 kmHigh 26.3°C · Low 16.8°C · 32 mm rain
- Magé in AugustBrazil · 32 kmHigh 25.3°C · Low 16.0°C · 44 mm rain
- Nova Iguaçu in AugustBrazil · 32 kmHigh 26.4°C · Low 16.4°C · 32 mm rain
- Maricá in AugustBrazil · 37 kmHigh 25.1°C · Low 18.2°C · 38 mm rain
- Itaboraí in AugustBrazil · 38 kmHigh 24.9°C · Low 15.8°C · 43 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Rio de Janeiro) is explained once on the Rio de Janeiro year overview and on the Sources, method and limits page.
Barra da Tijuca lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.