San Francisco climate — normals and trends
San Francisco (Argentina) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 18.4 °C and it receives 1,015 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 January (25.0 °C on average) and the coldest is July (11.5 °C). Rainfall peaks in March.
San Francisco averages 4 frost days, 68 hot days (≥ 30 °C) and 90 rainy days per year.
No statistically significant temperature trend emerges for San Francisco between 1940 and 2025: over this span, year-to-year swings outweigh the climate signal.
The hottest day of the period reached 41.9 °C (on 29 December 1971) and the coldest -5.6 °C (on 10 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
San FranciscoCordoba
- coords
- -31.42°, -62.08°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
18.4°C
Average daily high
24.1°C
Average daily low
13.5°C
Annual rainfall
1,015mm
Sunshine / day
9.7h
Mean relative humidity
70%
Average peak wind
17.8km/h
Seasonal range
13.5°C
Frost days (< 0 °C)
4 d/yr
Hot days (≥ 30 °C)
68 d/yr
Rainy days (≥ 1 mm)
90 d/yr
Annual snowfall
0.0 cm
Average feels-like high
24.3 °C
Average feels-like low
12.3 °C
Average peak gust
34.1 km/h
Tropical nights (≥ 20 °C)
51 d/yr
Solar radiation
17.7 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
41.9 °C
29 December 1971
Coldest day
-5.6 °C
10 July 2024
Wettest day
133 mm
12 March 2005
Windiest day
46.7 km/h
8 June 1973
Strongest gust
87.8 km/h
12 January 2010
Hottest feels-like
45.7 °C
3 February 2024
Coldest feels-like
-9.6 °C
10 July 2024
Snowiest day
1.6 cm
1 August 2011
Sunniest day
14.0 h
5 December 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 | 33.0 °C | +2.5 °C | 36 mm | -92 mm |
| Feb | 33.2 °C | +3.8 °C | 80 mm | -40 mm |
| Mar | 27.8 °C | +0.5 °C | 149 mm | +14 mm |
| Apr | 23.3 °C | -0.4 °C | 22 mm | -70 mm |
| May | 22.7 °C | +2.3 °C | 63 mm | +11 mm |
| Jun | 17.0 °C | -0.3 °C | 4 mm | -26 mm |
| Jul | 18.5 °C | +1.3 °C | 69 mm | +39 mm |
| Aug | 20.0 °C | +0.6 °C | 106 mm | +68 mm |
| Sep | 23.4 °C | +1.6 °C | 56 mm | -8 mm |
| Oct | 27.5 °C | +2.9 °C | 25 mm | -78 mm |
| Nov | 28.4 °C | +0.8 °C | 98 mm | -15 mm |
| Dec | 31.5 °C | +1.8 °C | 60 mm | -53 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 humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 18.4 °C and it receives 1,015 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 29 December 1971, reaching 41.9 °C.
What is the coldest day in San Francisco?
The coldest day measured in San Francisco between 1940 and 2025 was 10 July 2024, at -5.6 °C.
Does it snow in San Francisco?
Almost never: San Francisco sees virtually no snow, with about 4 frost days per year.
Has the climate of San Francisco warmed?
Between 1940 and 2025, no statistically significant temperature trend emerges in San Francisco.
What is the wettest day in San Francisco?
The wettest day measured in San Francisco between 1940 and 2025 was 12 March 2005, with 133 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 8 June 1973, with winds reaching 46.7 km/h.
What is the warmest month in San Francisco?
The warmest month in San Francisco is January (25.0 °C on average); the coldest is July (11.5 °C).
How much does it rain in San Francisco?
San Francisco receives on average 1,015 mm of precipitation per year, spread over about 90 rainy days.
Is it sunny in San Francisco?
San Francisco gets on average 9.7 hours of sunshine per day, roughly 3,540 hours per year over 1940-2025.
What is the biggest single-day snowfall in San Francisco?
The heaviest 24-hour snowfall measured in San Francisco between 1940 and 2025 was 1 August 2011, with 1.6 cm.
Are there tropical nights in San Francisco?
Yes: San Francisco has on average 51 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 45.7 °C on 3 February 2024, and the lowest was -9.6 °C on 10 July 2024.
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