São Sebastião climate — normals and trends
São Sebastião (Brazil) has a tropical rainforest climate (Af) under the Köppen-Geiger classification. Its mean annual temperature is 21.8 °C and it receives 1,990 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 February (24.9 °C on average) and the coldest is July (19.0 °C). Rainfall peaks in January.
São Sebastião averages 0 frost days, 8 hot days (≥ 30 °C) and 192 rainy days per year.
São Sebastião has warmed by +1.4 °C between 1940 and 2025, or +0.16 °C per decade. This trend is statistically significant.
The hottest day of the period reached 35.6 °C (on 2 October 2020) and the coldest 10.2 °C (on 18 July 1975).
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 SebastiãoSão Paulo
- coords
- -23.76°, -45.41°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
21.8°C
Average daily high
23.7°C
Average daily low
20.2°C
Annual rainfall
1,990mm
Sunshine / day
9.5h
Mean relative humidity
85%
Average peak wind
14.0km/h
Seasonal range
5.9°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
8 d/yr
Rainy days (≥ 1 mm)
192 d/yr
Annual snowfall
0.0 cm
Average feels-like high
26.8 °C
Average feels-like low
21.9 °C
Average peak gust
29.7 km/h
Tropical nights (≥ 20 °C)
187 d/yr
Solar radiation
16.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.4 °C
since 1940
+0.2 °C per decade · r² = 0.50 · 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
35.6 °C
2 October 2020
Coldest day
10.2 °C
18 July 1975
Wettest day
257 mm
21 January 1984
Windiest day
44.3 km/h
17 December 1947
Strongest gust
89.3 km/h
17 December 1947
Hottest feels-like
43.2 °C
4 February 2010
Coldest feels-like
6.4 °C
21 July 1981
Sunniest day
13.5 h
16 December 1942
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 | 27.1 °C | +0.7 °C | 240 mm | -37 mm |
| Feb | 29.2 °C | +2.4 °C | 162 mm | -82 mm |
| Mar | 26.2 °C | +0.3 °C | 93 mm | -142 mm |
| Apr | 24.6 °C | +0.1 °C | 237 mm | +91 mm |
| May | 23.7 °C | +0.9 °C | 65 mm | -57 mm |
| Jun | 22.0 °C | 0.0 °C | 57 mm | -29 mm |
| Jul | 19.9 °C | -1.4 °C | 56 mm | -32 mm |
| Aug | 20.7 °C | -0.9 °C | 33 mm | -53 mm |
| Sep | 21.8 °C | 0.0 °C | 56 mm | -70 mm |
| Oct | 22.0 °C | -0.6 °C | 143 mm | -20 mm |
| Nov | 23.3 °C | -0.3 °C | 102 mm | -79 mm |
| Dec | 26.9 °C | +1.8 °C | 167 mm | -74 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 Sebastião?
São Sebastião has a tropical rainforest climate (Köppen Af). Over 1940-2025, the average annual temperature is 21.8 °C and it receives 1,990 mm of precipitation per year.
What is the hottest day ever recorded in São Sebastião?
The hottest day measured in São Sebastião between 1940 and 2025 was 2 October 2020, reaching 35.6 °C.
What is the coldest day in São Sebastião?
The coldest day measured in São Sebastião between 1940 and 2025 was 18 July 1975, at 10.2 °C.
Does it snow in São Sebastião?
Almost never: São Sebastião sees virtually no snow, with about 0 frost days per year.
Has the climate of São Sebastião warmed?
Yes: São Sebastião warmed by +1.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in São Sebastião?
The wettest day measured in São Sebastião between 1940 and 2025 was 21 January 1984, with 257 mm of rain in 24 hours.
What was the windiest day in São Sebastião?
The windiest day measured in São Sebastião between 1940 and 2025 was 17 December 1947, with winds reaching 44.3 km/h.
What is the warmest month in São Sebastião?
The warmest month in São Sebastião is February (24.9 °C on average); the coldest is July (19.0 °C).
How much does it rain in São Sebastião?
São Sebastião receives on average 1,990 mm of precipitation per year, spread over about 192 rainy days.
Is it sunny in São Sebastião?
São Sebastião gets on average 9.5 hours of sunshine per day, roughly 3,468 hours per year over 1940-2025.
Are there tropical nights in São Sebastião?
Yes: São Sebastião has on average 187 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in São Sebastião?
In São Sebastião, between 1940 and 2025, the highest apparent temperature reached 43.2 °C on 4 February 2010, and the lowest was 6.4 °C on 21 July 1981.
Compare São Sebastião with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around São Sebastião