Climate averages 1991–2020
Petrópolis weather
in September.
A warm, moderately wet month: the 8th warmest and the 5th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Petrópolis: daytime highs average 23.8°C and nights cool to about 15.1°C. By daytime temperature it is the 8th warmest of the 12 months.
Expect about 88 mm of rain on roughly 11 days, which makes September a moderately wet month (the 5th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 57 min on an average September day.
The nearest other city in this atlas is Magé (22 km away). In September its highs average 26.3°C, 2.5°C warmer than Petrópolis, with 85 mm of rain.
Among the 448 cities listed in Brazil, Petrópolis ranks joint 367th of 448 for the warmest September highs and 320th of 448 for the driest September (rainfall, lowest first). The mean September high of those 448 cities is 27.5°C; Petrópolis is 3.7°C cooler than that mean.
From September to October, average highs rise by 1.0°C to 24.8°C, and monthly rainfall rises from 88 mm to 137 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
Petrópolis climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 26.9°C19.6°C | 19.6°C | 315 | 22.9 | 13.313 h |
| February | 27.3°C19.6°C | 19.6°C | 233 | 18.5 | 12.913 h |
| March | 25.9°C19.0°C | 19.0°C | 244 | 22.0 | 12.212 h |
| April | 24.3°C17.4°C | 17.4°C | 105 | 14.0 | 11.612 h |
| May | 22.0°C14.8°C | 14.8°C | 70 | 10.9 | 11.111 h |
| June | 21.6°C13.6°C | 13.6°C | 41 | 7.0 | 10.811 h |
| July | 21.4°C13.0°C | 13.0°C | 39 | 6.6 | 10.911 h |
| August | 22.5°C13.5°C | 13.5°C | 42 | 7.2 | 11.311 h |
| September, selected | 23.8°C15.1°C | 15.1°C | 88 | 10.8 | 11.912 h |
| October | 24.8°C16.7°C | 16.7°C | 137 | 15.1 | 12.613 h |
| November | 24.6°C17.5°C | 17.5°C | 252 | 20.0 | 13.213 h |
| December | 26.1°C18.9°C | 18.9°C | 295 | 23.2 | 13.513 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
- Magé in SeptemberBrazil · 22 kmHigh 26.3°C · Low 17.6°C · 85 mm rain
- Teresópolis in SeptemberBrazil · 23 kmHigh 23.0°C · Low 14.6°C · 102 mm rain
- Duque de Caxias in SeptemberBrazil · 34 kmHigh 27.1°C · Low 18.2°C · 86 mm rain
- Belford Roxo in SeptemberBrazil · 37 kmHigh 27.3°C · Low 18.3°C · 66 mm rain
- São Gonçalo in SeptemberBrazil · 38 kmHigh 26.3°C · Low 18.1°C · 85 mm rain
- Nova Iguaçu in SeptemberBrazil · 40 kmHigh 27.4°C · Low 18.1°C · 66 mm rain
- Itaboraí in SeptemberBrazil · 42 kmHigh 25.9°C · Low 17.4°C · 82 mm rain
- Três Rios in SeptemberBrazil · 43 kmHigh 26.8°C · Low 17.0°C · 59 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 Petrópolis) is explained once on the Petrópolis year overview and on the Sources, method and limits page.