São Luís climate — normals and trends
São Luís (Brazil) has a tropical monsoon climate (Am) under the Köppen-Geiger classification. Its mean annual temperature is 26.6 °C and it receives 2,221 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 August (27.1 °C on average) and the coldest is February (26.0 °C). Rainfall peaks in March.
São Luís averages 0 frost days, 5 hot days (≥ 30 °C) and 224 rainy days per year.
São Luís has warmed by +0.7 °C between 1940 and 2025, or +0.08 °C per decade. This trend is statistically significant.
The hottest day of the period reached 31.5 °C (on 18 August 2015) and the coldest 22.9 °C (on 5 April 1943).
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
São LuísMaranhão
- coords
- -2.53°, -44.30°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
26.6°C
Average daily high
28.0°C
Average daily low
25.6°C
Annual rainfall
2,221mm
Sunshine / day
10.8h
Mean relative humidity
82%
Average peak wind
22.1km/h
Seasonal range
1.1°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
5 d/yr
Rainy days (≥ 1 mm)
224 d/yr
Annual snowfall
0.0 cm
Average feels-like high
32.0 °C
Average feels-like low
28.6 °C
Average peak gust
32.8 km/h
Tropical nights (≥ 20 °C)
364 d/yr
Solar radiation
19.5 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+0.7 °C
since 1940
+0.1 °C per decade · r² = 0.33 · p = < 0.001
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
31.5 °C
18 August 2015
Coldest day
22.9 °C
5 April 1943
Wettest day
214 mm
15 February 1980
Windiest day
40.4 km/h
9 November 1965
Strongest gust
54.4 km/h
6 December 1981
Hottest feels-like
37.6 °C
15 September 2017
Coldest feels-like
23.9 °C
10 May 1988
Sunniest day
12.0 h
2 January 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 27.9 °C | +0.4 °C | 461 mm | +208 mm |
| Feb | 27.7 °C | +0.4 °C | 362 mm | +20 mm |
| Mar | 27.9 °C | +0.7 °C | 462 mm | +7 mm |
| Apr | 28.3 °C | +0.9 °C | 363 mm | -53 mm |
| May | 28.9 °C | +1.0 °C | 153 mm | -156 mm |
| Jun | 28.8 °C | +0.6 °C | 118 mm | -55 mm |
| Jul | 29.0 °C | +0.7 °C | 80 mm | -23 mm |
| Aug | 29.3 °C | +0.6 °C | 35 mm | +5 mm |
| Sep | 29.3 °C | +0.9 °C | 9 mm | -5 mm |
| Oct | 29.0 °C | +0.7 °C | 13 mm | +1 mm |
| Nov | 28.6 °C | +0.2 °C | 16 mm | -7 mm |
| Dec | 28.4 °C | +0.2 °C | 64 mm | -29 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 São Luís?
São Luís has a tropical monsoon climate (Köppen Am). Over 1940-2025, the average annual temperature is 26.6 °C and it receives 2,221 mm of precipitation per year.
What is the hottest day ever recorded in São Luís?
The hottest day measured in São Luís between 1940 and 2025 was 18 August 2015, reaching 31.5 °C.
What is the coldest day in São Luís?
The coldest day measured in São Luís between 1940 and 2025 was 5 April 1943, at 22.9 °C.
Does it snow in São Luís?
Almost never: São Luís sees virtually no snow, with about 0 frost days per year.
Has the climate of São Luís warmed?
Yes: São Luís warmed by +0.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in São Luís?
The wettest day measured in São Luís between 1940 and 2025 was 15 February 1980, with 214 mm of rain in 24 hours.
What was the windiest day in São Luís?
The windiest day measured in São Luís between 1940 and 2025 was 9 November 1965, with winds reaching 40.4 km/h.
What is the warmest month in São Luís?
The warmest month in São Luís is August (27.1 °C on average); the coldest is February (26.0 °C).
How much does it rain in São Luís?
São Luís receives on average 2,221 mm of precipitation per year, spread over about 224 rainy days.
Is it sunny in São Luís?
São Luís gets on average 10.8 hours of sunshine per day, roughly 3,942 hours per year over 1940-2025.
Are there tropical nights in São Luís?
Yes: São Luís has on average 364 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in São Luís?
In São Luís, between 1940 and 2025, the highest apparent temperature reached 37.6 °C on 15 September 2017, and the lowest was 23.9 °C on 10 May 1988.
Compare São Luís with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around São Luís