Climate averages 1991–2020
Grajaú weather
in September.
A very hot, very dry month: the warmest and the 4th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a very hot month in Grajaú: daytime highs average 34.4°C and nights cool to about 23.5°C. By daytime temperature it is the warmest month of the year.
Expect about 8.9 mm of rain on roughly 2 days, which makes September a very dry month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 04 min on an average September day.
The nearest other city in this atlas is Barra do Corda (105 km away). In September its highs average 34.9°C, about as warm as Grajaú, with 10 mm of rain.
Among the 448 cities listed in Brazil, Grajaú ranks joint 16th of 448 for the warmest September highs and 43rd of 448 for the driest September (rainfall, lowest first). The mean September high of those 448 cities is 27.5°C; Grajaú is 6.9°C warmer than that mean.
From September to October, average highs fall by 0.6°C to 33.8°C, and monthly rainfall rises from 8.9 mm to 32 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
Grajaú climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 29.3°C22.6°C | 22.6°C | 172 | 24.7 | 12.412 h |
| February | 29.2°C22.6°C | 22.6°C | 177 | 24.0 | 12.312 h |
| March | 29.2°C22.6°C | 22.6°C | 188 | 26.1 | 12.112 h |
| April | 29.5°C22.6°C | 22.6°C | 132 | 20.4 | 12.012 h |
| May | 30.1°C22.3°C | 22.3°C | 64 | 10.5 | 11.912 h |
| June | 31.5°C22.1°C | 22.1°C | 8.4 | 1.6 | 11.812 h |
| July | 32.5°C22.2°C | 22.2°C | 4.7 | 0.8 | 11.812 h |
| August | 33.7°C22.6°C | 22.6°C | 1.9 | 0.3 | 11.912 h |
| September, selected | 34.4°C23.5°C | 23.5°C | 8.9 | 1.7 | 12.112 h |
| October | 33.8°C24.1°C | 24.1°C | 32 | 5.3 | 12.212 h |
| November | 32.1°C23.7°C | 23.7°C | 78 | 11.9 | 12.412 h |
| December | 30.7°C23.2°C | 23.2°C | 135 | 17.8 | 12.512 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
- Barra do Corda in SeptemberBrazil · 105 kmHigh 34.9°C · Low 23.9°C · 10 mm rain
- Imperatriz in SeptemberBrazil · 153 kmHigh 34.5°C · Low 24.5°C · 9.6 mm rain
- Açailândia in SeptemberBrazil · 180 kmHigh 33.6°C · Low 22.9°C · 14 mm rain
- Balsas in SeptemberBrazil · 191 kmHigh 35.1°C · Low 24.1°C · 8.6 mm rain
- Bacabal in SeptemberBrazil · 232 kmHigh 34.9°C · Low 24.7°C · 7.4 mm rain
- Santa Inês in SeptemberBrazil · 254 kmHigh 34.0°C · Low 24.3°C · 12 mm rain
- Araguaína in SeptemberBrazil · 275 kmHigh 34.2°C · Low 22.6°C · 25 mm rain
- Codó in SeptemberBrazil · 292 kmHigh 35.2°C · Low 24.2°C · 6.2 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 Grajaú) is explained once on the Grajaú year overview and on the Sources, method and limits page.