Climate Overview
The climate in Rio Branco is hot. The average annual temperature is 26°C and approximately 1771mm of precipitation falls per year. January is the wettest month, receiving around 285mm of rainfall. Rio Branco sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
Rio Branco sees moderate temperature variation throughout the year, ranging from 19°C to 34°C. The warmest month is September, when average highs reach 34°C and the mean temperature sits around 27°C. July is the coolest month, with minimum temperatures around 19°C and an average of 25°C. On average, daily temperatures fluctuate by about 9°C between overnight lows and afternoon highs.
Precipitation
Rio Branco is a fairly wet location, receiving approximately 1771mm of precipitation annually, which averages out to around 148mm per month. The wettest month is January, averaging 285mm of rainfall. February and March also tend to see above-average precipitation. The driest month is July, with just 10mm. That's 275mm 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 Branco is relatively calm, with an average annual wind speed of 9km/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 10km/h, though still comfortable for most outdoor activities. The calmest conditions occur in May, with average winds dropping to 8km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 2km/h between the calmest and windiest months.
Seasons
89 days until Winter
It is currently autumn in Rio Branco, which began on March 20, 2026. Rio Branco sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in September at around 34°C, while the coldest stretch bottoms out in July near 19°C. Winter is next, beginning on June 21, 2026 — 89 days from now.
Spring
Temperatures range from 23 to 34°C. Rainfall is heavy, totalling around 366mm across the season with a monthly average of 122mm. Winds are generally light, averaging 9km/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 814mm across the season with a monthly average of 271mm. Winds are generally light, averaging 9km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 21 to 30°C. Rainfall is heavy, totalling around 524mm across the season with a monthly average of 175mm. Winds are generally light, averaging 9km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 19 to 34°C. Rainfall is relatively light, with around 67mm over the season and a monthly average of 22mm. Winds are generally light, averaging 9km/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 Branco is during June, when the weather is most comfortable for travellers. During these months, average temperatures hover around 24°C with modest rainfall averaging 27mm per month. By contrast, September can be uncomfortably hot with highs reaching 34°C, while July is the coldest period with lows dropping to 19°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.
Monthly Climate Data
The table below shows monthly climate averages for Rio Branco 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.
