Climate averages 1991–2020
Altamira weather
by month.
See how the year changes. September has the highest average daily maximum; August has the lowest average monthly rainfall.
Long-term climate patterns, not a forecast for a particular trip.
Across the year Altamira averages a daytime high of 30.2°C and a nighttime low of 23.4°C, with about 1,817 mm of rain on roughly 227 days. September is the warmest month (average high 33.1°C) and April (tied with February and March) the coolest (28.5°C). March is the wettest month with 328 mm; August is the driest with 31 mm.
The annual picture
A year in Altamira
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 | 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
Nearby cities
- BrevesBrazil · 256 kmHigh 30.8°C · Low 23.9°C · 2,134 mm rain a year
- TucuruíBrazil · 287 kmHigh 30.7°C · Low 24.3°C · 2,088 mm rain a year
- SantarémBrazil · 290 kmHigh 29.4°C · Low 25.2°C · 3,035 mm rain a year
- CametáBrazil · 319 kmHigh 30.8°C · Low 24.2°C · 2,321 mm rain a year
- TailândiaBrazil · 362 kmHigh 31.4°C · Low 23.3°C · 1,928 mm rain a year
- SantanaBrazil · 370 kmHigh 29.8°C · Low 23.9°C · 2,055 mm rain a year
- MacapáBrazil · 382 kmHigh 29.5°C · Low 24.0°C · 2,366 mm rain a year
- São Félix do XinguBrazil · 383 kmHigh 30.5°C · Low 22.6°C · 1,922 mm rain a year
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 limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC-3, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at -3.20°, -52.20° (1 km from the city centre), adjusted up by 0.2°C for the difference between the city's elevation (101 m) and the cell's (125 m). Rain comes from the 0.25° cell at -3.25°, -52.25°. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.