Rohnert Park climate — normals and trends
Rohnert Park (United States) has a warm-summer mediterranean climate (Csb) under the Köppen-Geiger classification. Its mean annual temperature is 13.4 °C and it receives 687 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 (17.7 °C on average) and the coldest is January (8.4 °C). Rainfall peaks in January.
Rohnert Park averages 5 frost days, 6 hot days (≥ 30 °C) and 59 rainy days per year.
Rohnert Park has warmed by +1.1 °C between 1940 and 2025, or +0.13 °C per decade. This trend is statistically significant.
The number of frost days there went from about 9 to 1 per year over the period.
The hottest day of the period reached 38.1 °C (on 3 September 1950) and the coldest -3.7 °C (on 22 December 1990).
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
Rohnert ParkCalifornia
- coords
- 38.34°, -122.70°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
13.4°C
Average daily high
18.9°C
Average daily low
8.8°C
Annual rainfall
687mm
Sunshine / day
10.4h
Mean relative humidity
75%
Average peak wind
14.9km/h
Seasonal range
9.3°C
Frost days (< 0 °C)
5 d/yr
Hot days (≥ 30 °C)
6 d/yr
Rainy days (≥ 1 mm)
59 d/yr
Annual snowfall
0.2 cm
Average feels-like high
18.1 °C
Average feels-like low
7.0 °C
Average peak gust
32.9 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
18.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.1 °C
since 1940
+0.1 °C per decade · r² = 0.34 · 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
38.1 °C
3 September 1950
Coldest day
-3.7 °C
22 December 1990
Wettest day
108 mm
24 October 2021
Windiest day
46.1 km/h
24 February 1958
Strongest gust
110.9 km/h
12 December 1995
Hottest feels-like
39.1 °C
2 June 1960
Coldest feels-like
-8.1 °C
22 December 1990
Snowiest day
5.8 cm
3 January 1974
Sunniest day
14.4 h
3 July 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 | 15.4 °C | +2.3 °C | 28 mm | -106 mm |
| Feb | 15.0 °C | +0.5 °C | 197 mm | +70 mm |
| Mar | 15.3 °C | -0.3 °C | 112 mm | +9 mm |
| Apr | 17.8 °C | +0.3 °C | 15 mm | -36 mm |
| May | 21.6 °C | +1.6 °C | 1 mm | -20 mm |
| Jun | 21.5 °C | -1.2 °C | 0 mm | -5 mm |
| Jul | 21.2 °C | -2.9 °C | 1 mm | +0 mm |
| Aug | 24.9 °C | +0.7 °C | 0 mm | -1 mm |
| Sep | 23.5 °C | -0.5 °C | 6 mm | +0 mm |
| Oct | 20.6 °C | -0.7 °C | 33 mm | -2 mm |
| Nov | 17.2 °C | +0.7 °C | 88 mm | +4 mm |
| Dec | 13.6 °C | +0.3 °C | 146 mm | +24 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 Rohnert Park?
Rohnert Park has a warm-summer mediterranean climate (Köppen Csb). Over 1940-2025, the average annual temperature is 13.4 °C and it receives 687 mm of precipitation per year.
What is the hottest day ever recorded in Rohnert Park?
The hottest day measured in Rohnert Park between 1940 and 2025 was 3 September 1950, reaching 38.1 °C.
What is the coldest day in Rohnert Park?
The coldest day measured in Rohnert Park between 1940 and 2025 was 22 December 1990, at -3.7 °C.
Does it snow in Rohnert Park?
Almost never: Rohnert Park sees virtually no snow, with about 5 frost days per year.
Has the climate of Rohnert Park warmed?
Yes: Rohnert Park warmed by +1.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Rohnert Park?
The wettest day measured in Rohnert Park between 1940 and 2025 was 24 October 2021, with 108 mm of rain in 24 hours.
What was the windiest day in Rohnert Park?
The windiest day measured in Rohnert Park between 1940 and 2025 was 24 February 1958, with winds reaching 46.1 km/h.
What is the warmest month in Rohnert Park?
The warmest month in Rohnert Park is August (17.7 °C on average); the coldest is January (8.4 °C).
How much does it rain in Rohnert Park?
Rohnert Park receives on average 687 mm of precipitation per year, spread over about 59 rainy days.
Is it sunny in Rohnert Park?
Rohnert Park 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 Rohnert Park?
The heaviest 24-hour snowfall measured in Rohnert Park between 1940 and 2025 was 3 January 1974, with 5.8 cm.
Are there tropical nights in Rohnert Park?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Rohnert Park.
What was the most extreme apparent temperature in Rohnert Park?
In Rohnert Park, between 1940 and 2025, the highest apparent temperature reached 39.1 °C on 2 June 1960, and the lowest was -8.1 °C on 22 December 1990.
Compare Rohnert Park with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Rohnert Park