Norco climate — normals and trends
Norco (United States) has a hot-summer mediterranean climate (Csa) under the Köppen-Geiger classification. Its mean annual temperature is 16.8 °C and it receives 470 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 (24.8 °C on average) and the coldest is January (10.0 °C). Rainfall peaks in February.
Norco averages 5 frost days, 90 hot days (≥ 30 °C) and 45 rainy days per year.
Norco has warmed by +2.2 °C between 1940 and 2025, or +0.26 °C per decade. This trend is statistically significant.
The number of frost days there went from about 10 to 0 per year over the period.
The hottest day of the period reached 46.1 °C (on 6 September 2020) and the coldest -8.3 °C (on 12 January 1949).
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
NorcoCalifornia
- coords
- 33.93°, -117.55°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
16.8°C
Average daily high
23.8°C
Average daily low
11.2°C
Annual rainfall
470mm
Sunshine / day
11.2h
Mean relative humidity
59%
Average peak wind
9.9km/h
Seasonal range
14.8°C
Frost days (< 0 °C)
5 d/yr
Hot days (≥ 30 °C)
90 d/yr
Rainy days (≥ 1 mm)
45 d/yr
Annual snowfall
1.6 cm
Average feels-like high
23.2 °C
Average feels-like low
10.0 °C
Average peak gust
29.3 km/h
Tropical nights (≥ 20 °C)
24 d/yr
Solar radiation
20.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.2 °C
since 1940
+0.3 °C per decade · r² = 0.55 · 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
46.1 °C
6 September 2020
Coldest day
-8.3 °C
12 January 1949
Wettest day
106 mm
29 November 1970
Windiest day
30.7 km/h
16 March 1964
Strongest gust
88.6 km/h
1 March 1983
Hottest feels-like
45.7 °C
6 September 2020
Coldest feels-like
-12.6 °C
12 January 1949
Snowiest day
10.6 cm
29 January 1957
Sunniest day
14.0 h
12 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 | 18.1 °C | +1.7 °C | 23 mm | -67 mm |
| Feb | 19.9 °C | +2.7 °C | 110 mm | +11 mm |
| Mar | 18.2 °C | -0.4 °C | 90 mm | +12 mm |
| Apr | 21.6 °C | +0.2 °C | 20 mm | -18 mm |
| May | 25.9 °C | +1.6 °C | 10 mm | -4 mm |
| Jun | 29.6 °C | +1.1 °C | 2 mm | -1 mm |
| Jul | 31.1 °C | -1.3 °C | 0 mm | -1 mm |
| Aug | 33.8 °C | +1.3 °C | 1 mm | -3 mm |
| Sep | 30.4 °C | -0.3 °C | 15 mm | +6 mm |
| Oct | 26.5 °C | +0.5 °C | 46 mm | +26 mm |
| Nov | 22.1 °C | +1.4 °C | 124 mm | +79 mm |
| Dec | 20.7 °C | +3.8 °C | 103 mm | +34 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 Norco?
Norco has a hot-summer mediterranean climate (Köppen Csa). Over 1940-2025, the average annual temperature is 16.8 °C and it receives 470 mm of precipitation per year.
What is the hottest day ever recorded in Norco?
The hottest day measured in Norco between 1940 and 2025 was 6 September 2020, reaching 46.1 °C.
What is the coldest day in Norco?
The coldest day measured in Norco between 1940 and 2025 was 12 January 1949, at -8.3 °C.
Does it snow in Norco?
Yes. Norco gets on average 1.6 cm of snow per year and has around 5 frost days.
Has the climate of Norco warmed?
Yes: Norco warmed by +2.2 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Norco?
The wettest day measured in Norco between 1940 and 2025 was 29 November 1970, with 106 mm of rain in 24 hours.
What was the windiest day in Norco?
The windiest day measured in Norco between 1940 and 2025 was 16 March 1964, with winds reaching 30.7 km/h.
What is the warmest month in Norco?
The warmest month in Norco is August (24.8 °C on average); the coldest is January (10.0 °C).
How much does it rain in Norco?
Norco receives on average 470 mm of precipitation per year, spread over about 45 rainy days.
Is it sunny in Norco?
Norco 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 Norco?
The heaviest 24-hour snowfall measured in Norco between 1940 and 2025 was 29 January 1957, with 10.6 cm.
Are there tropical nights in Norco?
Yes: Norco has on average 24 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Norco?
In Norco, between 1940 and 2025, the highest apparent temperature reached 45.7 °C on 6 September 2020, and the lowest was -12.6 °C on 12 January 1949.
Compare Norco with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Norco