Rio Branco Temperature by Month

Rio Branco in Acre, Brazil enjoys a stable climate, with daytime temperatures staying close to 32°C (90°F) throughout the year. Explore the full monthly breakdown below.

The temperature in Rio Branco remains steady throughout the year, providing a consistently very warm climate. Maximum daytime temperatures range from a very warm 35°C (95°F) in September to a very warm 31°C (88°F) in May. Nights are mild year-round, with lows ranging from 22°C (72°F) in September to 20°C (68°F) in May.

The chart below illustrates the average maximum day and minimum night temperatures in Rio Branco by month:

The coldest point of the day usually falls between 4 AM and 6 AM, with temperatures peaking around 3 PM. September, the city's warmest month, gets 159 hours of sunshine.

The chart below shows the average temperature throughout the year:

Rio Branco's average annual maximum temperature is 32°C (90°F). To put that in context, here's how it compares to a few well-known destinations:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

Queenstown, New Zealand averages 10°C (50°F) annually, remember seasons are flipped, so its coldest months fall in June and July.

Boston, USA averages 16°C (61°F) annually, with four distinct seasons and cold winters that rival northern Europe.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In Rio Branco, May is the coolest month, with average highs of 31°C (88°F) and humidity around 86%, considered very high. In September, the warmest month, temperatures average 35°C (95°F) with 78% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on Rio Branco's weather, including monthly rainfall, sunshine hours, and humidity, visit our Rio Branco climate page.