Climate averages 1991–2020
Castanhal weather
in September.
A hot, fairly dry month: the 3rd warmest and one of the driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Castanhal: daytime highs average 32.3°C and nights cool to about 23.4°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 34 mm of rain on roughly 9 days, which makes September a fairly dry month (one of the driest months of the year). Daylight, from sunrise to sunset, lasts about 12 h 06 min on an average September day.
The nearest other city in this atlas is Santa Isabel do Pará (26 km away). In September its highs average 32.0°C, about as warm as Castanhal, with 39 mm of rain.
Among the 448 cities listed in Brazil, Castanhal ranks joint 63rd of 448 for the warmest September highs and joint 111th of 448 for the driest September (rainfall, lowest first). The mean September high of those 448 cities is 27.5°C; Castanhal is 4.8°C warmer than that mean.
From September to October, average highs rise by 0.8°C to 33.1°C, and monthly rainfall stays at 34 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
Castanhal climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 29.8°C23.3°C | 23.3°C | 269 | 27.0 | 12.212 h |
| February | 29.0°C23.0°C | 23.0°C | 357 | 27.2 | 12.212 h |
| March | 28.9°C22.9°C | 22.9°C | 456 | 30.5 | 12.112 h |
| April | 28.9°C23.0°C | 23.0°C | 427 | 29.6 | 12.112 h |
| May | 29.4°C23.0°C | 23.0°C | 278 | 27.7 | 12.112 h |
| June | 29.7°C22.7°C | 22.7°C | 120 | 21.4 | 12.012 h |
| July | 30.0°C22.6°C | 22.6°C | 91 | 18.1 | 12.112 h |
| August | 31.2°C23.0°C | 23.0°C | 51 | 12.7 | 12.112 h |
| September, selected | 32.3°C23.4°C | 23.4°C | 34 | 8.6 | 12.112 h |
| October | 33.1°C23.7°C | 23.7°C | 34 | 8.0 | 12.112 h |
| November | 32.9°C24.0°C | 24.0°C | 49 | 8.7 | 12.212 h |
| December | 31.8°C24.0°C | 24.0°C | 118 | 17.2 | 12.212 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
- Santa Isabel do Pará in SeptemberBrazil · 26 kmHigh 32.0°C · Low 23.7°C · 39 mm rain
- Marituba in SeptemberBrazil · 47 kmHigh 32.3°C · Low 23.9°C · 39 mm rain
- Ananindeua in SeptemberBrazil · 50 kmHigh 32.0°C · Low 24.1°C · 39 mm rain
- Belém in SeptemberBrazil · 67 kmHigh 31.7°C · Low 24.6°C · 24 mm rain
- Barcarena in SeptemberBrazil · 81 kmHigh 31.7°C · Low 24.8°C · 19 mm rain
- Capanema in SeptemberBrazil · 84 kmHigh 31.7°C · Low 23.7°C · 31 mm rain
- Moju in SeptemberBrazil · 114 kmHigh 33.4°C · Low 24.0°C · 27 mm rain
- Abaetetuba in SeptemberBrazil · 116 kmHigh 32.4°C · Low 24.8°C · 19 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 Castanhal) is explained once on the Castanhal year overview and on the Sources, method and limits page.