Climate averages 1991–2020
Rio Grande weather
in December.
A warm, moderately wet month: the 4th warmest and the 2nd driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
December is a warm month in Rio Grande: daytime highs average 23.2°C and nights cool to about 20.2°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 86 mm of rain on roughly 8 days, which makes December a moderately wet month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 12 min on an average December day.
The nearest other city in this atlas is Pelotas (37 km away). In December its highs average 25.2°C, 2.0°C warmer than Rio Grande, with 100 mm of rain.
Among the 448 cities listed in Brazil, Rio Grande ranks 448th of 448 for the warmest December highs and joint 80th of 448 for the driest December (rainfall, lowest first). The mean December high of those 448 cities is 28.5°C; Rio Grande is 5.3°C cooler than that mean.
From December to January, average highs rise by 1.5°C to 24.6°C, and monthly rainfall rises from 86 mm to 87 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 Grande climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 24.6°C21.9°C | 21.9°C | 87 | 8.6 | 14.014 h |
| February | 24.9°C22.3°C | 22.3°C | 85 | 9.8 | 13.213 h |
| March | 24.0°C21.4°C | 21.4°C | 92 | 9.9 | 12.312 h |
| April | 21.7°C18.8°C | 18.8°C | 112 | 10.1 | 11.311 h |
| May | 18.6°C15.8°C | 15.8°C | 104 | 9.8 | 10.511 h |
| June | 16.1°C13.0°C | 13.0°C | 110 | 9.7 | 10.110 h |
| July | 15.0°C11.7°C | 11.7°C | 112 | 10.1 | 10.310 h |
| August | 15.8°C12.5°C | 12.5°C | 108 | 9.6 | 11.011 h |
| September | 16.7°C13.7°C | 13.7°C | 125 | 10.2 | 11.912 h |
| October | 18.9°C16.1°C | 16.1°C | 129 | 10.1 | 12.913 h |
| November | 21.0°C18.0°C | 18.0°C | 87 | 7.7 | 13.714 h |
| December, selected | 23.2°C20.2°C | 20.2°C | 86 | 8.0 | 14.214 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
- Pelotas in DecemberBrazil · 37 kmHigh 25.2°C · Low 19.1°C · 100 mm rain
- Bagé in DecemberBrazil · 206 kmHigh 27.5°C · Low 17.1°C · 117 mm rain
- Guaíba in DecemberBrazil · 226 kmHigh 28.4°C · Low 19.3°C · 124 mm rain
- Cachoeira do Sul in DecemberBrazil · 235 kmHigh 28.7°C · Low 18.7°C · 132 mm rain
- Porto Alegre in DecemberBrazil · 238 kmHigh 28.4°C · Low 19.2°C · 124 mm rain
- Viamão in DecemberBrazil · 240 kmHigh 27.4°C · Low 19.2°C · 129 mm rain
- Alvorada in DecemberBrazil · 246 kmHigh 28.1°C · Low 19.3°C · 129 mm rain
- Canoas in DecemberBrazil · 251 kmHigh 28.4°C · Low 19.1°C · 124 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 Grande) is explained once on the Rio Grande year overview and on the Sources, method and limits page.