Clearlake climate — normals and trends
Clearlake (United States) has a hot-summer mediterranean climate (Csa) under the Köppen-Geiger classification. Its mean annual temperature is 14.1 °C and it receives 792 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 (23.5 °C on average) and the coldest is January (6.2 °C). Rainfall peaks in January.
Clearlake averages 14 frost days, 56 hot days (≥ 30 °C) and 68 rainy days per year.
Clearlake has warmed by +2.0 °C between 1940 and 2025, or +0.23 °C per decade. This trend is statistically significant.
The number of frost days there went from about 22 to 6 per year over the period.
The hottest day of the period reached 42.4 °C (on 7 August 1981) and the coldest -10.5 °C (on 23 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
ClearlakeCalifornia
- coords
- 38.96°, -122.63°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
14.1°C
Average daily high
19.9°C
Average daily low
9.2°C
Annual rainfall
792mm
Sunshine / day
10.4h
Mean relative humidity
63%
Average peak wind
11.3km/h
Seasonal range
17.3°C
Frost days (< 0 °C)
14 d/yr
Hot days (≥ 30 °C)
56 d/yr
Rainy days (≥ 1 mm)
68 d/yr
Annual snowfall
22.9 cm
Average feels-like high
18.5 °C
Average feels-like low
7.3 °C
Average peak gust
34.2 km/h
Tropical nights (≥ 20 °C)
10 d/yr
Solar radiation
18.6 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.0 °C
since 1940
+0.2 °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
42.4 °C
7 August 1981
Coldest day
-10.5 °C
23 January 1949
Wettest day
135 mm
8 January 1995
Windiest day
33.9 km/h
12 October 1962
Strongest gust
118.1 km/h
7 November 2002
Hottest feels-like
43.2 °C
8 August 1978
Coldest feels-like
-15.3 °C
25 January 1949
Snowiest day
31.7 cm
25 December 1948
Sunniest day
14.6 h
6 July 1945
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 | 14.4 °C | +3.6 °C | 32 mm | -118 mm |
| Feb | 13.1 °C | +0.6 °C | 214 mm | +79 mm |
| Mar | 13.8 °C | -0.4 °C | 118 mm | +5 mm |
| Apr | 19.6 °C | +2.2 °C | 16 mm | -40 mm |
| May | 24.2 °C | +2.5 °C | 8 mm | -22 mm |
| Jun | 29.0 °C | +2.5 °C | 1 mm | -9 mm |
| Jul | 30.0 °C | -0.7 °C | 3 mm | +2 mm |
| Aug | 31.8 °C | +1.7 °C | 1 mm | -3 mm |
| Sep | 27.1 °C | -0.3 °C | 29 mm | +19 mm |
| Oct | 20.6 °C | -1.2 °C | 58 mm | +13 mm |
| Nov | 16.6 °C | +1.7 °C | 109 mm | +14 mm |
| Dec | 12.9 °C | +1.9 °C | 210 mm | +68 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 Clearlake?
Clearlake has a hot-summer mediterranean climate (Köppen Csa). Over 1940-2025, the average annual temperature is 14.1 °C and it receives 792 mm of precipitation per year.
What is the hottest day ever recorded in Clearlake?
The hottest day measured in Clearlake between 1940 and 2025 was 7 August 1981, reaching 42.4 °C.
What is the coldest day in Clearlake?
The coldest day measured in Clearlake between 1940 and 2025 was 23 January 1949, at -10.5 °C.
Does it snow in Clearlake?
Yes. Clearlake gets on average 22.9 cm of snow per year and has around 14 frost days.
Has the climate of Clearlake warmed?
Yes: Clearlake warmed by +2.0 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Clearlake?
The wettest day measured in Clearlake between 1940 and 2025 was 8 January 1995, with 135 mm of rain in 24 hours.
What was the windiest day in Clearlake?
The windiest day measured in Clearlake between 1940 and 2025 was 12 October 1962, with winds reaching 33.9 km/h.
What is the warmest month in Clearlake?
The warmest month in Clearlake is July (23.5 °C on average); the coldest is January (6.2 °C).
How much does it rain in Clearlake?
Clearlake receives on average 792 mm of precipitation per year, spread over about 68 rainy days.
Is it sunny in Clearlake?
Clearlake 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 Clearlake?
The heaviest 24-hour snowfall measured in Clearlake between 1940 and 2025 was 25 December 1948, with 31.7 cm.
Are there tropical nights in Clearlake?
Yes: Clearlake has on average 10 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Clearlake?
In Clearlake, between 1940 and 2025, the highest apparent temperature reached 43.2 °C on 8 August 1978, and the lowest was -15.3 °C on 25 January 1949.
Compare Clearlake with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Clearlake