Chico climate — normals and trends
Chico (United States) has a hot-summer mediterranean climate (Csa) under the Köppen-Geiger classification. Its mean annual temperature is 16.5 °C and it receives 1,004 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 (27.2 °C on average) and the coldest is January (7.7 °C). Rainfall peaks in January.
Chico averages 11 frost days, 107 hot days (≥ 30 °C) and 72 rainy days per year.
Chico has warmed by +2.4 °C between 1940 and 2025, or +0.29 °C per decade. This trend is statistically significant.
The number of frost days there went from about 17 to 5 per year over the period.
The hottest day of the period reached 46.2 °C (on 14 July 1972) and the coldest -12.6 °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
ChicoCalifornia
- coords
- 39.73°, -121.84°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
16.5°C
Average daily high
23.1°C
Average daily low
10.5°C
Annual rainfall
1,004mm
Sunshine / day
10.5h
Mean relative humidity
52%
Average peak wind
14.2km/h
Seasonal range
19.5°C
Frost days (< 0 °C)
11 d/yr
Hot days (≥ 30 °C)
107 d/yr
Rainy days (≥ 1 mm)
72 d/yr
Annual snowfall
14.7 cm
Average feels-like high
21.4 °C
Average feels-like low
7.8 °C
Average peak gust
34.1 km/h
Tropical nights (≥ 20 °C)
22 d/yr
Solar radiation
18.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.4 °C
since 1940
+0.3 °C per decade · r² = 0.64 · 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
46.2 °C
14 July 1972
Coldest day
-12.6 °C
22 December 1990
Wettest day
139 mm
12 October 1962
Windiest day
46.5 km/h
4 January 2008
Strongest gust
121.0 km/h
4 January 2008
Hottest feels-like
47.5 °C
7 August 1978
Coldest feels-like
-18.0 °C
22 December 1990
Snowiest day
19.8 cm
4 January 1982
Sunniest day
14.4 h
24 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 | 16.1 °C | +3.2 °C | 51 mm | -135 mm |
| Feb | 15.4 °C | +0.4 °C | 387 mm | +222 mm |
| Mar | 16.6 °C | -0.5 °C | 177 mm | +33 mm |
| Apr | 22.8 °C | +1.9 °C | 37 mm | -36 mm |
| May | 29.2 °C | +3.3 °C | 16 mm | -23 mm |
| Jun | 34.0 °C | +2.8 °C | 0 mm | -12 mm |
| Jul | 34.6 °C | -0.5 °C | 1 mm | -0 mm |
| Aug | 36.1 °C | +2.2 °C | 0 mm | -3 mm |
| Sep | 31.1 °C | +0.2 °C | 16 mm | +2 mm |
| Oct | 23.2 °C | -1.4 °C | 57 mm | -1 mm |
| Nov | 18.7 °C | +1.7 °C | 117 mm | -12 mm |
| Dec | 14.6 °C | +1.7 °C | 316 mm | +135 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 Chico?
Chico has a hot-summer mediterranean climate (Köppen Csa). Over 1940-2025, the average annual temperature is 16.5 °C and it receives 1,004 mm of precipitation per year.
What is the hottest day ever recorded in Chico?
The hottest day measured in Chico between 1940 and 2025 was 14 July 1972, reaching 46.2 °C.
What is the coldest day in Chico?
The coldest day measured in Chico between 1940 and 2025 was 22 December 1990, at -12.6 °C.
Does it snow in Chico?
Yes. Chico gets on average 14.7 cm of snow per year and has around 11 frost days.
Has the climate of Chico warmed?
Yes: Chico warmed by +2.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Chico?
The wettest day measured in Chico between 1940 and 2025 was 12 October 1962, with 139 mm of rain in 24 hours.
What was the windiest day in Chico?
The windiest day measured in Chico between 1940 and 2025 was 4 January 2008, with winds reaching 46.5 km/h.
What is the warmest month in Chico?
The warmest month in Chico is July (27.2 °C on average); the coldest is January (7.7 °C).
How much does it rain in Chico?
Chico receives on average 1,004 mm of precipitation per year, spread over about 72 rainy days.
Is it sunny in Chico?
Chico gets on average 10.5 hours of sunshine per day, roughly 3,833 hours per year over 1940-2025.
What is the biggest single-day snowfall in Chico?
The heaviest 24-hour snowfall measured in Chico between 1940 and 2025 was 4 January 1982, with 19.8 cm.
Are there tropical nights in Chico?
Yes: Chico has on average 22 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Chico?
In Chico, between 1940 and 2025, the highest apparent temperature reached 47.5 °C on 7 August 1978, and the lowest was -18.0 °C on 22 December 1990.
Compare Chico with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Chico