Climate averages 1991–2020
Rio das Ostras weather
in August.
A warm, fairly dry month: the 10th warmest and the 3rd 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 das Ostras: daytime highs average 25.0°C and nights cool to about 17.8°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 34 mm of rain on roughly 7 days, which makes August a fairly dry month (the 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 20 min on an average August day.
The nearest other city in this atlas is Macaé (23 km away). In August its highs average 24.6°C, about as warm as Rio das Ostras, with 31 mm of rain.
Among the 448 cities listed in Brazil, Rio das Ostras ranks joint 268th of 448 for the warmest August highs and joint 225th of 448 for the driest August (rainfall, lowest first). The mean August high of those 448 cities is 26.2°C; Rio das Ostras is 1.2°C cooler than that mean.
From August to September, average highs rise by 0.8°C to 25.7°C, and monthly rainfall rises from 34 mm to 73 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 das Ostras climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 29.4°C23.2°C | 23.2°C | 206 | 16.5 | 13.313 h |
| February | 29.8°C23.4°C | 23.4°C | 141 | 12.8 | 12.913 h |
| March | 28.6°C22.8°C | 22.8°C | 172 | 17.6 | 12.212 h |
| April | 27.2°C21.3°C | 21.3°C | 85 | 12.1 | 11.612 h |
| May | 25.1°C19.1°C | 19.1°C | 60 | 9.5 | 11.111 h |
| June | 24.7°C17.9°C | 17.9°C | 31 | 5.9 | 10.811 h |
| July | 24.4°C17.4°C | 17.4°C | 29 | 5.6 | 10.911 h |
| August, selected | 25.0°C17.8°C | 17.8°C | 34 | 6.5 | 11.311 h |
| September | 25.7°C18.9°C | 18.9°C | 73 | 10.0 | 11.912 h |
| October | 26.6°C20.2°C | 20.2°C | 108 | 11.9 | 12.613 h |
| November | 26.8°C21.0°C | 21.0°C | 203 | 17.5 | 13.213 h |
| December | 28.4°C22.4°C | 22.4°C | 222 | 19.0 | 13.513 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
- Macaé in AugustBrazil · 23 kmHigh 24.6°C · Low 18.2°C · 31 mm rain
- São Pedro da Aldeia in AugustBrazil · 38 kmHigh 23.4°C · Low 19.0°C · 31 mm rain
- Cabo Frio in AugustBrazil · 41 kmHigh 23.4°C · Low 19.4°C · 28 mm rain
- Araruama in AugustBrazil · 56 kmHigh 23.4°C · Low 19.1°C · 42 mm rain
- Nova Friburgo in AugustBrazil · 66 kmHigh 22.6°C · Low 13.7°C · 50 mm rain
- Saquarema in AugustBrazil · 68 kmHigh 23.8°C · Low 18.4°C · 36 mm rain
- Itaboraí in AugustBrazil · 97 kmHigh 24.9°C · Low 15.8°C · 43 mm rain
- Maricá in AugustBrazil · 100 kmHigh 25.1°C · Low 18.2°C · 38 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 das Ostras) is explained once on the Rio das Ostras year overview and on the Sources, method and limits page.