Climate averages 1991–2020
Rio de Janeiro weather
in December.
A hot, wet month: the 3rd warmest and the 11th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a hot month in Rio de Janeiro: daytime highs average 29.7°C and nights cool to about 22.6°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 151 mm of rain on roughly 16 days, which makes December a wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 31 min on an average December day.
The nearest other city in this atlas is São Gonçalo (16 km away). In December its highs average 29.1°C, 0.6°C cooler than Rio de Janeiro, with 229 mm of rain.
Among the 448 cities listed in Brazil, Rio de Janeiro ranks joint 120th of 448 for the warmest December highs and joint 142nd of 448 for the driest December (rainfall, lowest first). The mean December high of those 448 cities is 28.5°C; Rio de Janeiro is 1.2°C warmer than that mean.
From December to January, average highs rise by 1.0°C to 30.7°C, and monthly rainfall rises from 151 mm to 170 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 de Janeiro climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 30.7°C23.5°C | 23.5°C | 170 | 16.4 | 13.413 h |
| February | 31.2°C23.6°C | 23.6°C | 118 | 13.3 | 12.913 h |
| March | 29.6°C23.0°C | 23.0°C | 145 | 16.7 | 12.212 h |
| April | 28.0°C21.4°C | 21.4°C | 88 | 12.0 | 11.612 h |
| May | 25.6°C19.0°C | 19.0°C | 76 | 11.1 | 11.011 h |
| June | 25.2°C17.8°C | 17.8°C | 48 | 7.3 | 10.811 h |
| July | 24.9°C17.1°C | 17.1°C | 51 | 7.9 | 10.911 h |
| August | 25.9°C17.5°C | 17.5°C | 41 | 7.5 | 11.311 h |
| September | 26.8°C18.6°C | 18.6°C | 75 | 10.5 | 11.912 h |
| October | 28.0°C20.0°C | 20.0°C | 92 | 11.7 | 12.613 h |
| November | 28.0°C21.0°C | 21.0°C | 139 | 15.8 | 13.213 h |
| December, selected | 29.7°C22.6°C | 22.6°C | 151 | 16.2 | 13.514 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
- São Gonçalo in DecemberBrazil · 16 kmHigh 29.1°C · Low 22.1°C · 229 mm rain
- Duque de Caxias in DecemberBrazil · 19 kmHigh 29.8°C · Low 22.3°C · 237 mm rain
- Barra da Tijuca in DecemberBrazil · 21 kmHigh 30.2°C · Low 23.0°C · 151 mm rain
- Belford Roxo in DecemberBrazil · 27 kmHigh 30.0°C · Low 22.5°C · 192 mm rain
- Magé in DecemberBrazil · 32 kmHigh 29.1°C · Low 21.9°C · 229 mm rain
- Nova Iguaçu in DecemberBrazil · 32 kmHigh 30.0°C · Low 22.3°C · 192 mm rain
- Maricá in DecemberBrazil · 37 kmHigh 29.0°C · Low 23.0°C · 123 mm rain
- Itaboraí in DecemberBrazil · 38 kmHigh 28.7°C · Low 21.6°C · 255 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 de Janeiro) is explained once on the Rio de Janeiro year overview and on the Sources, method and limits page.
Barra da Tijuca lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.