Climate averages 1991–2020
Altamira weather
in September.
A hot, fairly dry month: the warmest and the 2nd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Altamira: daytime highs average 33.1°C and nights cool to about 24.2°C. By daytime temperature it is the warmest month of the year.
Expect about 34 mm of rain on roughly 7 days, which makes September a fairly dry month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 05 min on an average September day.
The nearest other city in this atlas is Breves (256 km away). In September its highs average 33.4°C, about as warm as Altamira, with 25 mm of rain.
Among the 448 cities listed in Brazil, Altamira ranks joint 46th 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; Altamira is 5.6°C warmer than that mean.
From September to October, average highs fall by 0.1°C to 33.0°C, and monthly rainfall rises from 34 mm to 60 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
Altamira climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 28.9°C23.0°C | 23.0°C | 248 | 28.1 | 12.312 h |
| February | 28.5°C22.9°C | 22.9°C | 276 | 26.8 | 12.212 h |
| March | 28.5°C22.9°C | 22.9°C | 328 | 29.1 | 12.112 h |
| April | 28.5°C23.0°C | 23.0°C | 280 | 28.2 | 12.012 h |
| May | 28.8°C23.1°C | 23.1°C | 190 | 26.1 | 12.012 h |
| June | 29.2°C22.9°C | 22.9°C | 71 | 16.5 | 11.912 h |
| July | 30.0°C22.8°C | 22.8°C | 46 | 10.1 | 12.012 h |
| August | 32.1°C23.5°C | 23.5°C | 31 | 7.1 | 12.012 h |
| September, selected | 33.1°C24.2°C | 24.2°C | 34 | 7.0 | 12.112 h |
| October | 33.0°C24.5°C | 24.5°C | 60 | 11.1 | 12.212 h |
| November | 31.9°C24.3°C | 24.3°C | 100 | 14.9 | 12.312 h |
| December | 30.4°C23.8°C | 23.8°C | 152 | 21.9 | 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
- Breves in SeptemberBrazil · 256 kmHigh 33.4°C · Low 24.5°C · 25 mm rain
- Tucuruí in SeptemberBrazil · 287 kmHigh 33.3°C · Low 25.2°C · 27 mm rain
- Santarém in SeptemberBrazil · 290 kmHigh 31.2°C · Low 26.2°C · 68 mm rain
- Cametá in SeptemberBrazil · 319 kmHigh 33.3°C · Low 24.7°C · 28 mm rain
- Tailândia in SeptemberBrazil · 362 kmHigh 34.4°C · Low 24.0°C · 22 mm rain
- Santana in SeptemberBrazil · 370 kmHigh 31.5°C · Low 24.7°C · 24 mm rain
- Macapá in SeptemberBrazil · 382 kmHigh 31.2°C · Low 24.8°C · 26 mm rain
- São Félix do Xingu in SeptemberBrazil · 383 kmHigh 33.7°C · Low 23.5°C · 41 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 Altamira) is explained once on the Altamira year overview and on the Sources, method and limits page.