Climate averages 1991–2020
Parnaíba weather
in September.
A hot, very dry month: the warmest and the driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Parnaíba: daytime highs average 33.8°C and nights cool to about 25.0°C. By daytime temperature it is the warmest month of the year.
Expect about 1.1 mm of rain on fewer than one day, which makes September a very dry month (the driest month of the year). Daylight, from sunrise to sunset, lasts about 12 h 05 min on an average September day.
The nearest other city in this atlas is Tianguá (127 km away). In September its highs average 30.9°C, 3.0°C cooler than Parnaíba, with 1.2 mm of rain.
Among the 448 cities listed in Brazil, Parnaíba ranks joint 30th of 448 for the warmest September highs and joint 7th of 448 for the driest September (rainfall, lowest first). The mean September high of those 448 cities is 27.5°C; Parnaíba is 6.3°C warmer than that mean.
From September to October, average highs fall by 0.3°C to 33.6°C, and monthly rainfall rises from 1.1 mm to 5.6 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
Parnaíba climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 30.1°C24.9°C | 24.9°C | 129 | 20.0 | 12.312 h |
| February | 29.4°C24.7°C | 24.7°C | 172 | 23.3 | 12.212 h |
| March | 29.1°C24.6°C | 24.6°C | 265 | 27.7 | 12.112 h |
| April | 29.2°C24.7°C | 24.7°C | 268 | 25.9 | 12.012 h |
| May | 30.0°C24.9°C | 24.9°C | 148 | 17.9 | 12.012 h |
| June | 31.0°C24.9°C | 24.9°C | 31 | 7.0 | 12.012 h |
| July | 32.2°C24.8°C | 24.8°C | 16 | 2.7 | 12.012 h |
| August | 33.4°C24.8°C | 24.8°C | 2.6 | 0.5 | 12.012 h |
| September, selected | 33.8°C25.0°C | 25.0°C | 1.1 | 0.2 | 12.112 h |
| October | 33.6°C25.2°C | 25.2°C | 5.6 | 0.7 | 12.212 h |
| November | 33.1°C25.5°C | 25.5°C | 7.4 | 1.6 | 12.212 h |
| December | 32.1°C25.5°C | 25.5°C | 35 | 7.1 | 12.312 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
- Tianguá in SeptemberBrazil · 127 kmHigh 30.9°C · Low 19.6°C · 1.2 mm rain
- Sobral in SeptemberBrazil · 181 kmHigh 35.5°C · Low 23.9°C · 1.0 mm rain
- Chapadinha in SeptemberBrazil · 199 kmHigh 34.9°C · Low 24.2°C · 3.5 mm rain
- Itapipoca in SeptemberBrazil · 253 kmHigh 34.1°C · Low 24.0°C · 2.7 mm rain
- São José de Ribamar in SeptemberBrazil · 257 kmHigh 30.1°C · Low 25.8°C · 11 mm rain
- Teresina in SeptemberBrazil · 268 kmHigh 36.5°C · Low 24.1°C · 3.3 mm rain
- Caxias in SeptemberBrazil · 279 kmHigh 36.1°C · Low 23.9°C · 5.0 mm rain
- Crateús in SeptemberBrazil · 281 kmHigh 34.3°C · Low 22.5°C · 1.3 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 Parnaíba) is explained once on the Parnaíba year overview and on the Sources, method and limits page.