Grajaú climate — normals and trends
Grajaú (Brazil) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 26.6 °C and it receives 1,021 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is September (28.5 °C on average) and the coldest is February (25.3 °C). Rainfall peaks in March.
Grajaú averages 0 frost days, 270 hot days (≥ 30 °C) and 151 rainy days per year.
No statistically significant temperature trend emerges for Grajaú between 1940 and 2025: over this span, year-to-year swings outweigh the climate signal.
The hottest day of the period reached 39.5 °C (on 18 October 1958) and the coldest 16.4 °C (on 22 July 2024).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
GrajaúMaranhão
- coords
- -5.82°, -46.14°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
26.6°C
Average daily high
31.7°C
Average daily low
22.4°C
Annual rainfall
1,021mm
Sunshine / day
10.4h
Mean relative humidity
72%
Average peak wind
12.2km/h
Seasonal range
3.2°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
270 d/yr
Rainy days (≥ 1 mm)
151 d/yr
Annual snowfall
0.0 cm
Average feels-like high
35.9 °C
Average feels-like low
25.3 °C
Average peak gust
31.4 km/h
Tropical nights (≥ 20 °C)
352 d/yr
Solar radiation
19.1 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
No clear trend over this period
Over a short window, year-to-year swings outweigh the climate signal. Try 86 years.
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
39.5 °C
18 October 1958
Coldest day
16.4 °C
22 July 2024
Wettest day
191 mm
16 December 1977
Windiest day
26.6 km/h
10 June 1980
Strongest gust
54.7 km/h
14 August 1942
Hottest feels-like
44.2 °C
28 October 2018
Coldest feels-like
15.7 °C
3 August 2022
Sunniest day
12.1 h
9 January 1944
Normals computed over complete calendar years 1940–2025.
A specific year
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Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 30.3 °C | +0.4 °C | 434 mm | +257 mm |
| Feb | 30.4 °C | +0.7 °C | 193 mm | +10 mm |
| Mar | 30.5 °C | +0.9 °C | 190 mm | -0 mm |
| Apr | 31.4 °C | +1.5 °C | 65 mm | -70 mm |
| May | 32.6 °C | +1.9 °C | 11 mm | -45 mm |
| Jun | 32.8 °C | +1.0 °C | 18 mm | +6 mm |
| Jul | 33.7 °C | +0.8 °C | 1 mm | -4 mm |
| Aug | 34.3 °C | +0.2 °C | 4 mm | -0 mm |
| Sep | 35.6 °C | +1.0 °C | 2 mm | -9 mm |
| Oct | 34.6 °C | +0.7 °C | 19 mm | -16 mm |
| Nov | 33.6 °C | +1.0 °C | 25 mm | -52 mm |
| Dec | 30.9 °C | -0.2 °C | 218 mm | +81 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Grajaú?
Grajaú has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 26.6 °C and it receives 1,021 mm of precipitation per year.
What is the hottest day ever recorded in Grajaú?
The hottest day measured in Grajaú between 1940 and 2025 was 18 October 1958, reaching 39.5 °C.
What is the coldest day in Grajaú?
The coldest day measured in Grajaú between 1940 and 2025 was 22 July 2024, at 16.4 °C.
Does it snow in Grajaú?
Almost never: Grajaú sees virtually no snow, with about 0 frost days per year.
Has the climate of Grajaú warmed?
Between 1940 and 2025, no statistically significant temperature trend emerges in Grajaú.
What is the wettest day in Grajaú?
The wettest day measured in Grajaú between 1940 and 2025 was 16 December 1977, with 191 mm of rain in 24 hours.
What was the windiest day in Grajaú?
The windiest day measured in Grajaú between 1940 and 2025 was 10 June 1980, with winds reaching 26.6 km/h.
What is the warmest month in Grajaú?
The warmest month in Grajaú is September (28.5 °C on average); the coldest is February (25.3 °C).
How much does it rain in Grajaú?
Grajaú receives on average 1,021 mm of precipitation per year, spread over about 151 rainy days.
Is it sunny in Grajaú?
Grajaú gets on average 10.4 hours of sunshine per day, roughly 3,796 hours per year over 1940-2025.
Are there tropical nights in Grajaú?
Yes: Grajaú has on average 352 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Grajaú?
In Grajaú, between 1940 and 2025, the highest apparent temperature reached 44.2 °C on 28 October 2018, and the lowest was 15.7 °C on 3 August 2022.
Compare Grajaú with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Grajaú