Clearlake, California climate: Normal weather by month, frost dates and records
Clearlake's normal year runs from 33°F January nights to 91°F July afternoons, with 29.9 inches of precipitation and less than an inch of snow (0.4 in) a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.8°C, January lows of 0°C, July highs of 33°C, 758 mm of precipitation a year.
- NOAA stationClearlake (4 mi SE)
- Station IDUSC00041806
- Location38.92°N 122.57°W
- Elevation1,349 ft (411 m)
- From the center4 miles
- Population16,636
On October 23, the normal high in Clearlake is 73°F and the normal low 41°F, and the chance of measurable rain or snow is 16%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Clearlake.
- Jan 55° 33°
- Feb 58° 34°
- Mar 62° 35°
- Apr 66° 39°
- May 73° 45°
- Jun 83° 52°
- Jul 91° 56°
- Aug 91° 54°
- Sep 85° 50°
- Oct 75° 43°
- Nov 63° 36°
- Dec 55° 33°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Clearlake each month?
July is the warmest month, with normal highs of 91°F; January the coldest, with normal lows of 33°F. The most precipitation falls in January (6.19 in), the least in July (0.01 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 55°F | 33°F | 43.7°F | 6.19 | 14 | <1 | 18 | 9 h 40 min |
| February | 58°F | 34°F | 45.7°F | 6.15 | 13 | <1 | 13 | 10 h 40 min |
| March | 62°F | 35°F | 48.5°F | 3.99 | 10 | <1 | 9 | 11 h 50 min |
| April | 66°F | 39°F | 52.8°F | 1.99 | 8 | <1 | 3 | 13 h 10 min |
| May | 73°F | 45°F | 58.8°F | 1.16 | 5 | 2 | <1 | 14 h 20 min |
| June | 83°F | 52°F | 67.3°F | 0.23 | 2 | 9 | <1 | 14 h 50 min |
| July | 91°F | 56°F | 73.6°F | 0.01 | <1 | 22 | <1 | 14 h 40 min |
| August | 91°F | 54°F | 72.4°F | 0.09 | <1 | 18 | <1 | 13 h 40 min |
| September | 85°F | 50°F | 67.9°F | 0.17 | 1 | 13 | <1 | 12 h 30 min |
| October | 75°F | 43°F | 59.3°F | 0.91 | 4 | 2 | 1 | 11 h 20 min |
| November | 63°F | 36°F | 49.5°F | 2.89 | 9 | <1 | 11 | 10 h 10 min |
| December | 55°F | 33°F | 43.7°F | 6.08 | 13 | <1 | 18 | 9 h 30 min |
| Year (annual) | 71°F | 42°F | 56.9°F | 29.86 | 79 | 66 | 72 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 13°C | 0°C | 6.5°C | 157 mm |
| February | 14°C | 1°C | 7.6°C | 156 mm |
| March | 16°C | 2°C | 9.2°C | 101 mm |
| April | 19°C | 4°C | 11.6°C | 51 mm |
| May | 23°C | 7°C | 14.9°C | 29 mm |
| June | 28°C | 11°C | 19.6°C | 6 mm |
| July | 33°C | 13°C | 23.1°C | 0 mm |
| August | 33°C | 12°C | 22.4°C | 2 mm |
| September | 30°C | 10°C | 19.9°C | 4 mm |
| October | 24°C | 6°C | 15.2°C | 23 mm |
| November | 17°C | 2°C | 9.7°C | 73 mm |
| December | 13°C | 0°C | 6.5°C | 154 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00041806; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Clearlake?
Normal highs sit between 65°F and 85°F in April, May, June and October. Of those, June has the fewest days with rain (2).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00041806.
When is the last frost in Clearlake?
In Clearlake, the last spring frost (32°F) comes after April 10 in half of years and after April 30 in one year in ten; the first autumn frost comes before November 6 in half of years and before October 24 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 101 year in 10 after April 30; 9 in 10 after March 24
- First autumn frost, half of years before
- November 61 year in 10 before October 24; 9 in 10 before November 20
NOAA puts the median frost-free season at 209 days, and the season without a hard freeze (28°F) at 250 days.
A hard freeze (28°F) comes after March 14 in half of springs and before November 21 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Clearlake in zone 9a in ZIP code 95422.
Frost dates for every NOAA station in California · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00041806; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Clearlake?
In a normal year in Clearlake, 66 days a year reach 90°F (10 of them 100°F or more), 72 nights fall to 32°F or colder and 79 days bring measurable precipitation.
- Days at 90°F or more
- 66a normal year
- Days at 100°F or more
- 10a normal year
- Nights at 32°F or colder
- 72a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 79a normal year
The highest temperature in this station's record (since 1954) is 114°F, on June 30, 1977; the lowest is 6°F, on December 22, 1990.
The wettest calendar year on that record is 1983, with 61.88 in; the snowiest season is 1973–74, with 24.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00041806; records: ACIS (NOAA Regional Climate Centers), station USC00041806. Records use complete months only; a month missing more than three days is left out.
How sunny is Clearlake?
Over a year 87% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Clearlake, 5.1 kWh per square metre a day. July is the sunniest month (95%) and December the cloudiest (72%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 74% | 2.3 |
| February | 77% | 3.3 |
| March | 78% | 4.6 |
| April | 84% | 6.1 |
| May | 88% | 7.3 |
| June | 93% | 8.1 |
| July | 95% | 8.0 |
| August | 94% | 7.1 |
| September | 93% | 5.8 |
| October | 88% | 4.2 |
| November | 81% | 2.8 |
| December | 72% | 2.0 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Clearlake need?
A normal year in Clearlake brings 3,707 heating degree days, 31% fewer than the median U.S. place (5,373), and 788 cooling degree days, 13% fewer than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,335 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 660 | 0 |
| February | 540 | 0 |
| March | 512 | 0 |
| April | 365 | 1 |
| May | 213 | 20 |
| June | 50 | 120 |
| July | 3 | 271 |
| August | 3 | 233 |
| September | 37 | 122 |
| October | 198 | 22 |
| November | 465 | 0 |
| December | 660 | 0 |
| Year (annual) | 3,707 | 788 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00041806. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Clearlake's climate compare?
Clearlake is warmer than 48 of the other 218 places with their own NOAA record in California, and wetter than 167. Across the 7,247 U.S. stations with normals, its annual mean of 56.9°F is warmer than 66%.
In the Köppen classification computed from these normals, Clearlake is Csa: temperate, dry-summer, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Clearlake share this climate record?
11 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Hidden Valley Lake, CA5,896 people · 9 mi S
- Clearlake Riviera, CA4,287 people · 9 mi W
- Kelseyville, CA4,204 people · 15 mi W
- Lucerne, CA3,156 people · 14 mi NW
- Clearlake Oaks, CA2,174 people · 8 mi NW
- Soda Bay, CA968 people · 13 mi NW
- Cobb, CA928 people · 10 mi SW
- Spring Valley, CA775 people · 11 mi N
- Lower Lake, CA598 people · 2 mi W
- Guinda, CA262 people · 21 mi E
- Rumsey, CA113 people · 18 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Clearlake's climate
What is the coldest month in Clearlake?
January, with a normal high of 55°F and a normal low of 33°F. The warmest is July (91°F by day, 56°F at night).
Does it snow in Clearlake?
Rarely: NOAA's normal is 0.4 inch a year.
What is the rainiest month in Clearlake?
January, with 6.19 in of precipitation in a normal year; the driest is July with 0.01 in.
What plant hardiness zone is Clearlake in?
The USDA's 2023 map puts Clearlake in zone 9a in ZIP code 95422.
How late can frost come in Clearlake?
In half of years the last 32°F night comes after April 10; in one year in ten it comes after April 30. Waiting until April 30 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Clearlake in OctoberThis month day by day, its records and recent years
- California climateThe statewide normals and every place in the state
- Calistoga, CA23 miles from this station, 60.1°F a year
- Angwin, CA25 miles from this station, 57.4°F a year
- Healdsburg, CA26 miles from this station, 60.2°F a year
- Cloverdale, CA26 miles from this station, 61.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made