San Luis climate — normals and trends
San Luis (United States) has a hot desert climate (BWh) under the Köppen-Geiger classification. Its mean annual temperature is 23.8 °C and it receives 79 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 July (34.3 °C on average) and the coldest is January (13.9 °C). Rainfall peaks in December.
San Luis averages 0 frost days, 196 hot days (≥ 30 °C) and 15 rainy days per year.
San Luis has warmed by +2.2 °C between 1940 and 2025, or +0.26 °C per decade. This trend is statistically significant.
The hottest day of the period reached 49.3 °C (on 28 July 1995) and the coldest -3.8 °C (on 14 January 1963).
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 LuisArizona
- coords
- 32.49°, -114.78°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
23.8°C
Average daily high
30.8°C
Average daily low
17.5°C
Annual rainfall
79mm
Sunshine / day
11.5h
Mean relative humidity
34%
Average peak wind
15.9km/h
Seasonal range
20.4°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
196 d/yr
Rainy days (≥ 1 mm)
15 d/yr
Annual snowfall
0.0 cm
Average feels-like high
29.3 °C
Average feels-like low
15.6 °C
Average peak gust
31.3 km/h
Tropical nights (≥ 20 °C)
143 d/yr
Solar radiation
21.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.2 °C
since 1940
+0.3 °C per decade · r² = 0.65 · 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
49.3 °C
28 July 1995
Coldest day
-3.8 °C
14 January 1963
Wettest day
68 mm
25 September 1997
Windiest day
53.7 km/h
20 August 2023
Strongest gust
94.7 km/h
20 August 2023
Hottest feels-like
50.4 °C
24 August 2010
Coldest feels-like
-9.1 °C
13 January 1963
Snowiest day
0.1 cm
14 December 1967
Sunniest day
13.8 h
21 June 2025
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 | 20.9 °C | +0.3 °C | 0 mm | -9 mm |
| Feb | 26.8 °C | +3.8 °C | 0 mm | -10 mm |
| Mar | 27.3 °C | +1.2 °C | 5 mm | -2 mm |
| Apr | 30.5 °C | +0.4 °C | 0 mm | -3 mm |
| May | 35.1 °C | +1.0 °C | 1 mm | +0 mm |
| Jun | 39.8 °C | +0.9 °C | 1 mm | +1 mm |
| Jul | 41.0 °C | 0.0 °C | 0 mm | -5 mm |
| Aug | 42.0 °C | +1.6 °C | 6 mm | -5 mm |
| Sep | 37.5 °C | -0.3 °C | 6 mm | -4 mm |
| Oct | 33.0 °C | +1.0 °C | 2 mm | -4 mm |
| Nov | 26.9 °C | +1.9 °C | 27 mm | +21 mm |
| Dec | 24.5 °C | +4.1 °C | 2 mm | -9 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 Luis?
San Luis has a hot desert climate (Köppen BWh). Over 1940-2025, the average annual temperature is 23.8 °C and it receives 79 mm of precipitation per year.
What is the hottest day ever recorded in San Luis?
The hottest day measured in San Luis between 1940 and 2025 was 28 July 1995, reaching 49.3 °C.
What is the coldest day in San Luis?
The coldest day measured in San Luis between 1940 and 2025 was 14 January 1963, at -3.8 °C.
Does it snow in San Luis?
Almost never: San Luis sees virtually no snow, with about 0 frost days per year.
Has the climate of San Luis warmed?
Yes: San Luis warmed by +2.2 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in San Luis?
The wettest day measured in San Luis between 1940 and 2025 was 25 September 1997, with 68 mm of rain in 24 hours.
What was the windiest day in San Luis?
The windiest day measured in San Luis between 1940 and 2025 was 20 August 2023, with winds reaching 53.7 km/h.
What is the warmest month in San Luis?
The warmest month in San Luis is July (34.3 °C on average); the coldest is January (13.9 °C).
How much does it rain in San Luis?
San Luis receives on average 79 mm of precipitation per year, spread over about 15 rainy days.
Is it sunny in San Luis?
San Luis gets on average 11.5 hours of sunshine per day, roughly 4,198 hours per year over 1940-2025.
What is the biggest single-day snowfall in San Luis?
The heaviest 24-hour snowfall measured in San Luis between 1940 and 2025 was 14 December 1967, with 0.1 cm.
Are there tropical nights in San Luis?
Yes: San Luis has on average 143 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in San Luis?
In San Luis, between 1940 and 2025, the highest apparent temperature reached 50.4 °C on 24 August 2010, and the lowest was -9.1 °C on 13 January 1963.
Compare San Luis with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around San Luis