Climate averages 1991–2020
Rio Grande weather
in September.
A mild, wet month: the 9th warmest and the 11th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Rio Grande: daytime highs average 16.7°C and nights cool to about 13.7°C. By daytime temperature it is the 9th warmest of the 12 months.
Expect about 125 mm of rain on roughly 10 days, which makes September a wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 52 min on an average September day.
The nearest other city in this atlas is Pelotas (37 km away). In September its highs average 18.4°C, 1.6°C warmer than Rio Grande, with 141 mm of rain.
Among the 448 cities listed in Brazil, Rio Grande ranks 448th of 448 for the warmest September highs and 369th of 448 for the driest September (rainfall, lowest first). The mean September high of those 448 cities is 27.5°C; Rio Grande is 10.8°C cooler than that mean.
From September to October, average highs rise by 2.2°C to 18.9°C, and monthly rainfall rises from 125 mm to 129 mm.
The annual picture
September 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, selected | 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 | 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
September in nearby cities
- Pelotas in SeptemberBrazil · 37 kmHigh 18.4°C · Low 12.5°C · 141 mm rain
- Bagé in SeptemberBrazil · 206 kmHigh 19.6°C · Low 10.4°C · 139 mm rain
- Guaíba in SeptemberBrazil · 226 kmHigh 21.4°C · Low 12.8°C · 146 mm rain
- Cachoeira do Sul in SeptemberBrazil · 235 kmHigh 21.3°C · Low 12.0°C · 153 mm rain
- Porto Alegre in SeptemberBrazil · 238 kmHigh 21.6°C · Low 12.8°C · 146 mm rain
- Viamão in SeptemberBrazil · 240 kmHigh 20.8°C · Low 12.9°C · 147 mm rain
- Alvorada in SeptemberBrazil · 246 kmHigh 21.5°C · Low 12.9°C · 147 mm rain
- Canoas in SeptemberBrazil · 251 kmHigh 21.7°C · Low 12.8°C · 146 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.