Climate Overview
The climate in Rio das Ostras is hot. The average annual temperature is 28°C and approximately 304mm of precipitation falls per year. December is the wettest month, receiving around 33mm of rainfall. Rio das Ostras is in the Southern Hemisphere. The seasons are reversed — summer runs from December to February, while winter falls between June and August. The summer months are: January, October, September. The coldest months are January, February, March, when temperatures can drop to 23°C.
Temperature
Rio das Ostras has relatively stable temperatures year-round, staying within a 6°C range. The warmest month is January, when average highs reach 29°C and the mean temperature sits around 26°C. January is the coolest month, with minimum temperatures around 23°C and an average of 26°C. Daily temperature variation is modest, with an average difference of 2°C between highs and lows.
Precipitation
Rio das Ostras is a quite dry location, receiving approximately 304mm of precipitation annually, which averages out to around 25mm per month. The wettest month is January, averaging 33mm of rainfall. February and March also tend to see above-average precipitation. The driest month is October, with just 1mm. That's 31mm less than January, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.
Wind
Rio das Ostras is relatively calm, with an average annual wind speed of 4km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is December, averaging 6km/h, though still comfortable for most outdoor activities. The calmest conditions occur in February, with average winds dropping to 1km/h, making it an ideal period for wind-sensitive activities. Wind speeds vary significantly across the year, with a 5km/h difference between the calmest and windiest months. This level of variation is worth factoring into travel plans.
Seasons
16 days until Spring
It is currently winter in Rio das Ostras, which began on June 21, 2026. Rio das Ostras is in the Southern Hemisphere, where the seasons are reversed — spring starts in September, summer in December, autumn in March, and winter in June. The warmest period peaks in January at around 29°C, while the coldest stretch bottoms out in January near 23°C. Spring is next, beginning on September 23, 2026 — 16 days from now.
Spring
Temperatures range from 28 to 29°C. Precipitation is minimal, with only around 22mm for the entire season. Winds are generally light, averaging 5km/h. Light layers work well as temperatures warm through the season — a great time to be outdoors.
Summer
Temperatures range from 23 to 29°C. Rainfall is relatively light, with around 98mm over the season and a monthly average of 33mm. Winds are generally light, averaging 3km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 26 to 28°C. Rainfall is relatively light, with around 98mm over the season and a monthly average of 33mm. Winds are generally light, averaging 3km/h. Layered clothing works best as temperatures gradually cool — enjoy the crisp air and changing scenery.
Winter
Temperatures range from 27 to 29°C. Rainfall is relatively light, with around 85mm over the season and a monthly average of 28mm. Winds are generally light, averaging 4km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Monthly Climate Data
The table below shows monthly climate averages for Rio das Ostras based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
