Clearlake weather by month
What a typical year looks like in Clearlake, California: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at CLEARLAKE 4 SE, 7 km from Clearlake; records cover 1954–2026.
The year at a glance
- Precipitation a year
- 29.9 in758 mm
- Snow a year
- 0.4 in1 cm
- Last spring freeze
- Apr 9
- First fall freeze
- Nov 5
- Heating degree days
- 3,706
- Cooling degree days
- 788
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 22°−6° (heating, 99%) and 102°39° (cooling, 1%).
Month by month
Clearlake in January
Highs average 55°13° and lows 33°0°, with 6.2 in157 mm of precipitation and 0.2 in0.5 cm of snow in a typical January.
- Record high
- 80°27° (2014)
- Record low
- 8°−13° (1974)
- Heating degree days
- 660
- Cooling degree days
- 0
Clearlake in February
Highs average 58°14° and lows 34°1°, with 6.2 in156 mm of precipitation and 0.1 in0.3 cm of snow in a typical February.
- Record high
- 81°27° (1977)
- Record low
- 13°−11° (1984)
- Heating degree days
- 540
- Cooling degree days
- 0
Clearlake in March
Highs average 62°16° and lows 35°2°, with 4 in101 mm of precipitation and 0.1 in0.3 cm of snow in a typical March.
- Record high
- 93°34° (2026)
- Record low
- 17°−8° (1966)
- Heating degree days
- 512
- Cooling degree days
- 0
Clearlake in April
Highs average 66°19° and lows 39°4°, with 2 in51 mm of precipitation in a typical April.
- Record high
- 94°34° (1981)
- Record low
- 23°−5° (1964)
- Heating degree days
- 365
- Cooling degree days
- 1
Clearlake in May
Highs average 73°23° and lows 45°7°, with 1.2 in29 mm of precipitation in a typical May.
- Record high
- 101°38° (1984)
- Record low
- 28°−2° (1964)
- Heating degree days
- 213
- Cooling degree days
- 20
Clearlake in June
Highs average 83°28° and lows 52°11°, with 0.23 in5.8 mm of precipitation in a typical June.
- Record high
- 114°46° (1977)
- Record low
- 34°1° (1966)
- Heating degree days
- 50
- Cooling degree days
- 120
Clearlake in July
Highs average 91°33° and lows 56°13°, with 0.01 in0.3 mm of precipitation in a typical July.
- Record high
- 113°45° (1972)
- Record low
- 39°4° (1965)
- Heating degree days
- 3
- Cooling degree days
- 271
Clearlake in August
Highs average 91°33° and lows 54°12°, with 0.09 in2.3 mm of precipitation in a typical August.
- Record high
- 112°44° (1978)
- Record low
- 40°4° (1955)
- Heating degree days
- 3
- Cooling degree days
- 232
Clearlake in September
Highs average 85°30° and lows 50°10°, with 0.17 in4.3 mm of precipitation in a typical September.
- Record high
- 113°45° (2022)
- Record low
- 30°−1° (1965)
- Heating degree days
- 37
- Cooling degree days
- 122
Clearlake in OctoberThis month
Highs average 75°24° and lows 43°6°, with 0.91 in23 mm of precipitation in a typical October.
- Record high
- 102°39° (2024)
- Record low
- 24°−4° (1971)
- Heating degree days
- 198
- Cooling degree days
- 22
Clearlake in November
Highs average 63°17° and lows 36°2°, with 2.9 in73 mm of precipitation in a typical November.
- Record high
- 92°33° (1966)
- Record low
- 19°−7° (1956)
- Heating degree days
- 465
- Cooling degree days
- 0
Clearlake in December
Highs average 55°13° and lows 33°0°, with 6.1 in154 mm of precipitation in a typical December.
- Record high
- 79°26° (2021)
- Record low
- 6°−14° (1990)
- Heating degree days
- 660
- Cooling degree days
- 0