Walnut Park climate — normals and trends
Walnut Park (United States) has a hot-summer mediterranean climate (Csa) under the Köppen-Geiger classification. Its mean annual temperature is 17.4 °C and it receives 352 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 (23.4 °C on average) and the coldest is January (11.9 °C). Rainfall peaks in February.
Walnut Park averages 1 frost days, 62 hot days (≥ 30 °C) and 31 rainy days per year.
Walnut Park has warmed by +1.7 °C between 1940 and 2025, or +0.20 °C per decade. This trend is statistically significant.
The number of frost days there went from about 2 to 0 per year over the period.
The hottest day of the period reached 45.0 °C (on 6 July 2018) and the coldest -2.7 °C (on 8 December 1978).
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
Walnut ParkCalifornia
- coords
- 33.97°, -118.23°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
17.4°C
Average daily high
23.9°C
Average daily low
12.4°C
Annual rainfall
352mm
Sunshine / day
11.2h
Mean relative humidity
63%
Average peak wind
13.3km/h
Seasonal range
11.5°C
Frost days (< 0 °C)
1 d/yr
Hot days (≥ 30 °C)
62 d/yr
Rainy days (≥ 1 mm)
31 d/yr
Annual snowfall
0.1 cm
Average feels-like high
23.4 °C
Average feels-like low
11.5 °C
Average peak gust
30.2 km/h
Tropical nights (≥ 20 °C)
12 d/yr
Solar radiation
20.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.7 °C
since 1940
+0.2 °C per decade · r² = 0.44 · 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
45.0 °C
6 July 2018
Coldest day
-2.7 °C
8 December 1978
Wettest day
106 mm
9 January 2005
Windiest day
38.8 km/h
30 November 1982
Strongest gust
84.6 km/h
1 March 1983
Hottest feels-like
45.2 °C
3 September 1988
Coldest feels-like
-7.2 °C
4 January 1949
Snowiest day
1.5 cm
29 January 1957
Sunniest day
14.0 h
5 June 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 | 19.8 °C | +1.7 °C | 16 mm | -57 mm |
| Feb | 20.2 °C | +1.4 °C | 74 mm | -5 mm |
| Mar | 19.2 °C | -0.7 °C | 49 mm | -11 mm |
| Apr | 21.4 °C | -0.8 °C | 9 mm | -16 mm |
| May | 24.5 °C | +0.6 °C | 3 mm | -3 mm |
| Jun | 26.4 °C | -0.2 °C | 2 mm | +1 mm |
| Jul | 27.4 °C | -2.5 °C | 0 mm | -1 mm |
| Aug | 30.5 °C | 0.0 °C | 0 mm | -2 mm |
| Sep | 29.1 °C | -0.4 °C | 10 mm | +4 mm |
| Oct | 25.4 °C | -0.9 °C | 44 mm | +32 mm |
| Nov | 21.6 °C | -0.5 °C | 126 mm | +93 mm |
| Dec | 20.8 °C | +2.2 °C | 109 mm | +56 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 Walnut Park?
Walnut Park has a hot-summer mediterranean climate (Köppen Csa). Over 1940-2025, the average annual temperature is 17.4 °C and it receives 352 mm of precipitation per year.
What is the hottest day ever recorded in Walnut Park?
The hottest day measured in Walnut Park between 1940 and 2025 was 6 July 2018, reaching 45.0 °C.
What is the coldest day in Walnut Park?
The coldest day measured in Walnut Park between 1940 and 2025 was 8 December 1978, at -2.7 °C.
Does it snow in Walnut Park?
Almost never: Walnut Park sees virtually no snow, with about 1 frost days per year.
Has the climate of Walnut Park warmed?
Yes: Walnut Park warmed by +1.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Walnut Park?
The wettest day measured in Walnut Park between 1940 and 2025 was 9 January 2005, with 106 mm of rain in 24 hours.
What was the windiest day in Walnut Park?
The windiest day measured in Walnut Park between 1940 and 2025 was 30 November 1982, with winds reaching 38.8 km/h.
What is the warmest month in Walnut Park?
The warmest month in Walnut Park is August (23.4 °C on average); the coldest is January (11.9 °C).
How much does it rain in Walnut Park?
Walnut Park receives on average 352 mm of precipitation per year, spread over about 31 rainy days.
Is it sunny in Walnut Park?
Walnut Park gets on average 11.2 hours of sunshine per day, roughly 4,088 hours per year over 1940-2025.
What is the biggest single-day snowfall in Walnut Park?
The heaviest 24-hour snowfall measured in Walnut Park between 1940 and 2025 was 29 January 1957, with 1.5 cm.
Are there tropical nights in Walnut Park?
Yes: Walnut Park has on average 12 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Walnut Park?
In Walnut Park, between 1940 and 2025, the highest apparent temperature reached 45.2 °C on 3 September 1988, and the lowest was -7.2 °C on 4 January 1949.
Compare Walnut Park with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Walnut Park