Climate averages 1991–2020
Rio Branco weather
in December.
A hot, very wet month: the 6th warmest and the 10th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a hot month in Rio Branco: daytime highs average 29.5°C and nights cool to about 23.0°C. By daytime temperature it is the 6th warmest of the 12 months.
Expect about 246 mm of rain on roughly 26 days, which makes December a very wet month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 42 min on an average December day.
The nearest other city in this atlas is Riberalta (224 km away). In December its highs average 29.8°C, about as warm as Rio Branco, with 262 mm of rain.
Among the 448 cities listed in Brazil, Rio Branco ranks joint 137th of 448 for the warmest December highs and joint 381st of 448 for the driest December (rainfall, lowest first). The mean December high of those 448 cities is 28.5°C; Rio Branco is 1.0°C warmer than that mean.
From December to January, average highs fall by 0.1°C to 29.4°C, and monthly rainfall rises from 246 mm to 255 mm.
The annual picture
December 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 Branco climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 29.4°C22.9°C | 22.9°C | 255 | 27.6 | 12.613 h |
| February | 29.2°C22.8°C | 22.8°C | 243 | 25.3 | 12.412 h |
| March | 29.2°C22.8°C | 22.8°C | 249 | 27.2 | 12.212 h |
| April | 28.9°C22.4°C | 22.4°C | 160 | 22.7 | 11.912 h |
| May | 28.4°C21.6°C | 21.6°C | 76 | 15.4 | 11.712 h |
| June | 28.9°C20.9°C | 20.9°C | 30 | 6.8 | 11.612 h |
| July | 30.4°C20.4°C | 20.4°C | 21 | 4.2 | 11.612 h |
| August | 32.1°C21.4°C | 21.4°C | 38 | 6.3 | 11.812 h |
| September | 32.4°C22.7°C | 22.7°C | 76 | 11.9 | 12.012 h |
| October | 31.5°C23.0°C | 23.0°C | 137 | 19.5 | 12.312 h |
| November | 30.1°C22.9°C | 22.9°C | 199 | 22.9 | 12.613 h |
| December, selected | 29.5°C23.0°C | 23.0°C | 246 | 26.3 | 12.713 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
December in nearby cities
- Riberalta in DecemberBolivia · 224 kmHigh 29.8°C · Low 23.5°C · 262 mm rain
- Puerto Maldonado in DecemberPeru · 328 kmHigh 29.4°C · Low 23.0°C · 330 mm rain
- Porto Velho in DecemberBrazil · 449 kmHigh 29.7°C · Low 23.5°C · 298 mm rain
- Ariquemes in DecemberBrazil · 522 kmHigh 29.8°C · Low 22.9°C · 246 mm rain
- Cruzeiro do Sul in DecemberBrazil · 595 kmHigh 29.4°C · Low 22.7°C · 243 mm rain
- Cusco in DecemberPeru · 601 kmHigh 15.9°C · Low 8.4°C · 196 mm rain
- Trinidad in DecemberBolivia · 626 kmHigh 29.5°C · Low 23.6°C · 298 mm rain
- Ji Paraná in DecemberBrazil · 649 kmHigh 29.5°C · Low 23.0°C · 248 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 Branco) is explained once on the Rio Branco year overview and on the Sources, method and limits page.