San Fernando climate — normals and trends
San Fernando (Mexico) has a hot semi-arid climate (BSh) under the Köppen-Geiger classification. Its mean annual temperature is 23.7 °C and it receives 573 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 (29.0 °C on average) and the coldest is January (16.6 °C). Rainfall peaks in September.
San Fernando averages 0 frost days, 200 hot days (≥ 30 °C) and 87 rainy days per year.
San Fernando has warmed by +1.1 °C between 1940 and 2025, or +0.12 °C per decade. This trend is statistically significant.
The hottest day of the period reached 43.5 °C (on 27 May 1973) and the coldest -5.5 °C (on 24 December 1989).
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 FernandoTamaulipas
- coords
- 24.85°, -98.15°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
23.7°C
Average daily high
29.5°C
Average daily low
19.1°C
Annual rainfall
573mm
Sunshine / day
10.4h
Mean relative humidity
72%
Average peak wind
21.0km/h
Seasonal range
12.4°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
200 d/yr
Rainy days (≥ 1 mm)
87 d/yr
Annual snowfall
0.0 cm
Average feels-like high
31.0 °C
Average feels-like low
20.2 °C
Average peak gust
41.9 km/h
Tropical nights (≥ 20 °C)
199 d/yr
Solar radiation
18.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.1 °C
since 1940
+0.1 °C per decade · r² = 0.23 · 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
43.5 °C
27 May 1973
Coldest day
-5.5 °C
24 December 1989
Wettest day
237 mm
20 July 2005
Windiest day
67.9 km/h
20 July 2005
Strongest gust
149.8 km/h
20 July 2005
Hottest feels-like
50.7 °C
9 May 2024
Coldest feels-like
-12.0 °C
23 December 1989
Snowiest day
1.3 cm
25 December 2004
Sunniest day
13.0 h
30 April 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 | 20.4 °C | -2.0 °C | 15 mm | -11 mm |
| Feb | 25.9 °C | +1.3 °C | 6 mm | -19 mm |
| Mar | 31.4 °C | +3.7 °C | 16 mm | -13 mm |
| Apr | 32.5 °C | +1.7 °C | 12 mm | -31 mm |
| May | 34.9 °C | +2.1 °C | 44 mm | -8 mm |
| Jun | 34.3 °C | +0.1 °C | 132 mm | +72 mm |
| Jul | 33.9 °C | -0.8 °C | 82 mm | +23 mm |
| Aug | 36.2 °C | +1.1 °C | 45 mm | -12 mm |
| Sep | 33.4 °C | +0.8 °C | 142 mm | +35 mm |
| Oct | 32.2 °C | +2.4 °C | 31 mm | -28 mm |
| Nov | 29.9 °C | +3.7 °C | 20 mm | -9 mm |
| Dec | 26.1 °C | +2.6 °C | 22 mm | -2 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 Fernando?
San Fernando has a hot semi-arid climate (Köppen BSh). Over 1940-2025, the average annual temperature is 23.7 °C and it receives 573 mm of precipitation per year.
What is the hottest day ever recorded in San Fernando?
The hottest day measured in San Fernando between 1940 and 2025 was 27 May 1973, reaching 43.5 °C.
What is the coldest day in San Fernando?
The coldest day measured in San Fernando between 1940 and 2025 was 24 December 1989, at -5.5 °C.
Does it snow in San Fernando?
Almost never: San Fernando sees virtually no snow, with about 0 frost days per year.
Has the climate of San Fernando warmed?
Yes: San Fernando warmed by +1.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in San Fernando?
The wettest day measured in San Fernando between 1940 and 2025 was 20 July 2005, with 237 mm of rain in 24 hours.
What was the windiest day in San Fernando?
The windiest day measured in San Fernando between 1940 and 2025 was 20 July 2005, with winds reaching 67.9 km/h.
What is the warmest month in San Fernando?
The warmest month in San Fernando is August (29.0 °C on average); the coldest is January (16.6 °C).
How much does it rain in San Fernando?
San Fernando receives on average 573 mm of precipitation per year, spread over about 87 rainy days.
Is it sunny in San Fernando?
San Fernando gets on average 10.4 hours of sunshine per day, roughly 3,796 hours per year over 1940-2025.
What is the biggest single-day snowfall in San Fernando?
The heaviest 24-hour snowfall measured in San Fernando between 1940 and 2025 was 25 December 2004, with 1.3 cm.
Are there tropical nights in San Fernando?
Yes: San Fernando has on average 199 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in San Fernando?
In San Fernando, between 1940 and 2025, the highest apparent temperature reached 50.7 °C on 9 May 2024, and the lowest was -12.0 °C on 23 December 1989.
Compare San Fernando with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around San Fernando