Climate Overview
The climate in Rio das Ostras is warm and mild. The average annual temperature is 24°C and approximately 1319mm of precipitation falls per year. December is the wettest month, receiving around 215mm 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: February, January, March. The coldest months are July, August, June, when temperatures can drop to 17°C.
Temperature
Rio das Ostras sees moderate temperature variation throughout the year, ranging from 17°C to 31°C. The warmest month is February, when average highs reach 31°C and the mean temperature sits around 27°C. July is the coolest month, with minimum temperatures around 17°C and an average of 22°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows.
Precipitation
Rio das Ostras is a fairly wet location, receiving approximately 1319mm of precipitation annually, which averages out to around 110mm per month. The wettest month is December, averaging 215mm of rainfall. November and January also tend to see above-average precipitation. The driest month is July, with just 20mm. That's 195mm less than December, 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 October, averaging 5km/h, though still comfortable for most outdoor activities. The calmest conditions occur in March, with average winds dropping to 3km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 2km/h gap between the calmest and windiest months.
Seasons
12 days until Winter
It is currently autumn in Rio das Ostras, which began on March 20, 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 February at around 31°C, while the coldest stretch bottoms out in July near 17°C. Winter is next, beginning on June 21, 2026 — 12 days from now.
Spring
Temperatures range from 20 to 27°C. Rainfall is heavy, totalling around 389mm across the season with a monthly average of 130mm. Winds are generally light, averaging 5km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 23 to 31°C. Rainfall is heavy, totalling around 549mm across the season with a monthly average of 183mm. Winds are generally light, averaging 4km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 19 to 30°C. Precipitation is moderate at around 283mm for the season, averaging 94mm per month. Winds are generally light, averaging 4km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 17 to 26°C. Rainfall is relatively light, with around 98mm over the season and a monthly average of 33mm. Winds are generally light, averaging 4km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Best Time to Visit
The best time to visit Rio das Ostras is during April, May, June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 23°C with modest rainfall averaging 47mm per month. By contrast, February can be uncomfortably hot with temperatures reaching 31°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.
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.
