Climate averages 1991–2020
Rio das Ostras weather
in May.
A warm, moderately wet month: the 9th warmest and the 4th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a warm month in Rio das Ostras: daytime highs average 25.1°C and nights cool to about 19.1°C. By daytime temperature it is the 9th warmest of the 12 months.
Expect about 60 mm of rain on roughly 10 days, which makes May a moderately wet month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 03 min on an average May day.
The nearest other city in this atlas is Macaé (23 km away). In May its highs average 25.0°C, about as warm as Rio das Ostras, with 57 mm of rain.
Among the 448 cities listed in Brazil, Rio das Ostras ranks joint 228th of 448 for the warmest May highs and joint 182nd of 448 for the driest May (rainfall, lowest first). The mean May high of those 448 cities is 25.3°C; Rio das Ostras is 0.2°C cooler than that mean.
From May to June, average highs fall by 0.4°C to 24.7°C, and monthly rainfall falls from 60 mm to 31 mm.
The annual picture
May 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, selected | 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 | 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
May in nearby cities
- Macaé in MayBrazil · 23 kmHigh 25.0°C · Low 19.6°C · 57 mm rain
- São Pedro da Aldeia in MayBrazil · 38 kmHigh 24.1°C · Low 20.3°C · 57 mm rain
- Cabo Frio in MayBrazil · 41 kmHigh 24.3°C · Low 20.7°C · 58 mm rain
- Araruama in MayBrazil · 56 kmHigh 24.2°C · Low 20.5°C · 73 mm rain
- Nova Friburgo in MayBrazil · 66 kmHigh 22.3°C · Low 14.9°C · 80 mm rain
- Saquarema in MayBrazil · 68 kmHigh 24.3°C · Low 19.9°C · 76 mm rain
- Itaboraí in MayBrazil · 97 kmHigh 24.8°C · Low 17.5°C · 77 mm rain
- Maricá in MayBrazil · 100 kmHigh 25.2°C · Low 19.7°C · 77 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.