San Francisco climate — normals and trends
San Francisco (El Salvador) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 25.3 °C and it receives 1,592 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 April (27.2 °C on average) and the coldest is November (24.0 °C). Rainfall peaks in September.
San Francisco averages 0 frost days, 245 hot days (≥ 30 °C) and 164 rainy days per year.
San Francisco has warmed by +2.1 °C between 1940 and 2025, or +0.25 °C per decade. This trend is statistically significant.
The hottest day of the period reached 38.7 °C (on 19 February 2020) and the coldest 10.3 °C (on 6 December 1945).
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
San FranciscoMorazan
- coords
- 13.69°, -88.10°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
25.3°C
Average daily high
31.1°C
Average daily low
20.5°C
Annual rainfall
1,592mm
Sunshine / day
10.8h
Mean relative humidity
69%
Average peak wind
10.7km/h
Seasonal range
3.2°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
245 d/yr
Rainy days (≥ 1 mm)
164 d/yr
Annual snowfall
0.0 cm
Average feels-like high
34.1 °C
Average feels-like low
22.9 °C
Average peak gust
31.5 km/h
Tropical nights (≥ 20 °C)
255 d/yr
Solar radiation
20.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.1 °C
since 1940
+0.3 °C per decade · r² = 0.68 · 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
38.7 °C
19 February 2020
Coldest day
10.3 °C
6 December 1945
Wettest day
176 mm
31 May 1968
Windiest day
32.1 km/h
5 February 1996
Strongest gust
81.0 km/h
5 February 1996
Hottest feels-like
41.0 °C
28 May 2024
Coldest feels-like
7.8 °C
6 December 1945
Sunniest day
12.4 h
30 May 1943
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 | 32.3 °C | +0.9 °C | 7 mm | +5 mm |
| Feb | 34.1 °C | +1.5 °C | 4 mm | +1 mm |
| Mar | 34.7 °C | +1.2 °C | 10 mm | -6 mm |
| Apr | 34.1 °C | +0.7 °C | 56 mm | -12 mm |
| May | 33.1 °C | +1.7 °C | 110 mm | -136 mm |
| Jun | 31.3 °C | +1.5 °C | 266 mm | -1 mm |
| Jul | 33.7 °C | +2.5 °C | 82 mm | -67 mm |
| Aug | 34.0 °C | +2.9 °C | 80 mm | -117 mm |
| Sep | 31.7 °C | +2.2 °C | 365 mm | +49 mm |
| Oct | 29.7 °C | +0.7 °C | 425 mm | +160 mm |
| Nov | 30.5 °C | +1.0 °C | 24 mm | -32 mm |
| Dec | 31.5 °C | +1.0 °C | 22 mm | +15 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 San Francisco?
San Francisco has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 25.3 °C and it receives 1,592 mm of precipitation per year.
What is the hottest day ever recorded in San Francisco?
The hottest day measured in San Francisco between 1940 and 2025 was 19 February 2020, reaching 38.7 °C.
What is the coldest day in San Francisco?
The coldest day measured in San Francisco between 1940 and 2025 was 6 December 1945, at 10.3 °C.
Does it snow in San Francisco?
Almost never: San Francisco sees virtually no snow, with about 0 frost days per year.
Has the climate of San Francisco warmed?
Yes: San Francisco warmed by +2.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in San Francisco?
The wettest day measured in San Francisco between 1940 and 2025 was 31 May 1968, with 176 mm of rain in 24 hours.
What was the windiest day in San Francisco?
The windiest day measured in San Francisco between 1940 and 2025 was 5 February 1996, with winds reaching 32.1 km/h.
What is the warmest month in San Francisco?
The warmest month in San Francisco is April (27.2 °C on average); the coldest is November (24.0 °C).
How much does it rain in San Francisco?
San Francisco receives on average 1,592 mm of precipitation per year, spread over about 164 rainy days.
Is it sunny in San Francisco?
San Francisco gets on average 10.8 hours of sunshine per day, roughly 3,942 hours per year over 1940-2025.
Are there tropical nights in San Francisco?
Yes: San Francisco has on average 255 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in San Francisco?
In San Francisco, between 1940 and 2025, the highest apparent temperature reached 41.0 °C on 28 May 2024, and the lowest was 7.8 °C on 6 December 1945.
Compare San Francisco with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around San Francisco