Climate averages 1991–2020
São Sebastião (Sao Paulo), Brazil weather
in September.
A warm, wet month: the 10th warmest and the 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in São Sebastião (Sao Paulo), Brazil: daytime highs average 23.4°C and nights cool to about 19.0°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 132 mm of rain on roughly 14 days, which makes September a wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 56 min on an average September day.
The nearest other city in this atlas is Caraguatatuba (16 km away). In September its highs average 24.5°C, 1.1°C warmer than São Sebastião (Sao Paulo), Brazil, with 111 mm of rain.
Among the 448 cities listed in Brazil, São Sebastião (Sao Paulo), Brazil ranks joint 376th of 448 for the warmest September highs and joint 383rd of 448 for the driest September (rainfall, lowest first). The mean September high of those 448 cities is 27.5°C; São Sebastião (Sao Paulo), Brazil is 4.1°C cooler than that mean.
From September to October, average highs rise by 0.9°C to 24.3°C, and monthly rainfall rises from 132 mm to 146 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
São Sebastião (Sao Paulo), Brazil climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 27.8°C23.9°C | 23.9°C | 277 | 22.3 | 13.413 h |
| February | 28.1°C24.1°C | 24.1°C | 231 | 19.7 | 12.913 h |
| March | 27.2°C23.4°C | 23.4°C | 236 | 20.4 | 12.212 h |
| April | 26.0°C22.0°C | 22.0°C | 130 | 13.7 | 11.612 h |
| May | 24.1°C19.9°C | 19.9°C | 115 | 11.8 | 11.011 h |
| June | 23.5°C18.7°C | 18.7°C | 82 | 9.5 | 10.711 h |
| July | 22.9°C18.0°C | 18.0°C | 92 | 8.7 | 10.811 h |
| August | 23.0°C18.1°C | 18.1°C | 76 | 8.9 | 11.311 h |
| September, selected | 23.4°C19.0°C | 19.0°C | 132 | 13.8 | 11.912 h |
| October | 24.3°C20.2°C | 20.2°C | 146 | 15.2 | 12.613 h |
| November | 24.9°C21.0°C | 21.0°C | 187 | 17.5 | 13.213 h |
| December | 26.7°C22.7°C | 22.7°C | 214 | 19.2 | 13.614 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
- Caraguatatuba in SeptemberBrazil · 16 kmHigh 24.5°C · Low 18.7°C · 111 mm rain
- Ubatuba in SeptemberBrazil · 50 kmHigh 23.0°C · Low 18.3°C · 154 mm rain
- Jacareí in SeptemberBrazil · 76 kmHigh 25.2°C · Low 14.9°C · 77 mm rain
- Caçapava in SeptemberBrazil · 79 kmHigh 25.6°C · Low 15.0°C · 89 mm rain
- São José dos Campos in SeptemberBrazil · 81 kmHigh 25.5°C · Low 15.0°C · 77 mm rain
- Taubaté in SeptemberBrazil · 83 kmHigh 25.6°C · Low 14.7°C · 83 mm rain
- Mogi das Cruzes in SeptemberBrazil · 84 kmHigh 23.7°C · Low 14.2°C · 89 mm rain
- Pindamonhangaba in SeptemberBrazil · 93 kmHigh 26.2°C · Low 15.1°C · 83 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 São Sebastião) is explained once on the São Sebastião (Sao Paulo), Brazil year overview and on the Sources, method and limits page.