Clearlake, United States experiences average highs of 24°C (75°F) and lows of 11°C (52°F) throughout the year. The climate is relatively dry, with only 6 rainy days per month on average. Sunshine is abundant, averaging about 10 hours per day. Average highs have warmed by 0.8°C (1.4°F) across the available records.
Clearlake, United States Weather & Climate 2026
Monthly climate averages for Clearlake, United States. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: May–Oct 
Wetter season: Jan–Dec At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
7.3/10
Best: May, June, September, October
UV Index
6
High
Temperature 24°C / 11°C
Feels Like 23°C / 10°C
Rainy Days 6
Rainfall 66 mm
Sunshine 10 h
Humidity 58%
Wind Speed 12 km/h
Dew Point 9°C
Snow Days 2 days
Frost Days 2 days
Hottest Month
37°C
July
Avg Low20°C
Rain0days
Coldest Month
5°C
January
Avg High14°C
Rain11days
Driest Month
0days
July
Avg High37°C
Avg Low20°C
Windiest Month
13 km/h
March (Gusts 41)
Worst Time to Visit
Consider avoiding January, February, March, December due to frequent rain.
Sun Position
Sunrise 05:46
Daylight 14.9h
Sunset 20:39
Live conditions—
Clearlake on the map · live conditions
Clearlake, United States
- Continent
- Americas
- Country
- United States
- City
- Clearlake
- Population
- 15.2K
- Elevation
- 432 m
- Coordinates
- 38.96°, -122.63°
Seasonal Breakdown
Spring
Mar–May
Avg High 22°C
Avg Low 9°C
Rain 7 days/mo
1/3 best months
Summer
Jun–Aug
Avg High 35°C
Avg Low 19°C
Rain 1 days/mo
1/3 best months
Autumn
Sep–Nov
Avg High 25°C
Avg Low 12°C
Rain 4 days/mo
2/3 best months
Winter
Dec–Feb
Avg High 14°C
Avg Low 5°C
Rain 10 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 14°C / 5°C . Feb: 16°C / 5°C . Mar: 17°C / 5°C . Apr: 22°C / 8°C . May: 27°C / 12°C . Jun: 33°C / 17°C . Jul: 37°C / 20°C . Aug: 36°C / 20°C . Sep: 32°C / 17°C . Oct: 26°C / 13°C . Nov: 18°C / 8°C . Dec: 14°C / 5°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 166 mm. Feb: 140 mm. Mar: 128 mm. Apr: 40 mm. May: 31 mm. Jun: 4 mm. Jul: 1 mm. Aug: 2 mm. Sep: 11 mm. Oct: 44 mm. Nov: 86 mm. Dec: 136 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 77%. Feb: 68%. Mar: 71%. Apr: 63%. May: 56%. Jun: 44%. Jul: 39%. Aug: 42%. Sep: 47%. Oct: 51%. Nov: 66%. Dec: 74%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 11 km/h . Feb: 13 km/h . Mar: 13 km/h . Apr: 13 km/h . May: 13 km/h . Jun: 13 km/h . Jul: 12 km/h . Aug: 11 km/h . Sep: 11 km/h . Oct: 11 km/h . Nov: 10 km/h . Dec: 10 km/h .
Sunshine
Sunshine
Sunshine: Jan: 6h. Feb: 8h. Mar: 9h. Apr: 11h. May: 13h. Jun: 14h. Jul: 14h. Aug: 13h. Sep: 11h. Oct: 9h. Nov: 8h. Dec: 6h.
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 3. Feb: UV 3. Mar: UV 5. Apr: UV 7. May: UV 8. Jun: UV 8. Jul: UV 8. Aug: UV 8. Sep: UV 6. Oct: UV 5. Nov: UV 3. Dec: UV 2.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy Oppressive
Snow Days
Snow DaysSnowfall
Snow Days: Jan: 2 days. Feb: 2 days. Mar: 3 days. Apr: 0 days. May: 0 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 0 days. Oct: 0 days. Nov: 0 days. Dec: 1 days.
Climate Trends
Average highs have warmed by 0.8°C (1.4°F) across the available records. Average rainfall is trending drier by about 12 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Aug 2025 · 36°C | Jul · 37°C |
| Coldest month | Jan 2025 · 5°C | Jan · 5°C |
| Wettest month | Feb 2025 · 220 mm | Jan · 166 mm |
| Windiest month | Mar 2025 · 15 km/h | Mar · 13 km/h |
Month-by-Month Weather Table
January
Poor 
February
Fair March
Fair April
Good May best
Excellent June best
Excellent July
Good August
Good September best
Excellent October best
Excellent November
Good December
Fair | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 14°C / 5°C | 11°C / 2°C | 11days (166 mm) Wet | 6.2h Fair | 77% Humid | 2.7 Moderate | Poor | View Details |
| February | 16°C / 5°C | 13°C / 2°C | 8days (140 mm) Wet | 7.9h Good | 68% Muggy | 3.4 Moderate | Fair | View Details |
| March | 17°C / 5°C | 14°C / 3°C | 12days (128 mm) Wet | 8.8h Good | 71% Muggy | 4.8 Moderate | Fair | View Details |
| April | 22°C / 8°C | 20°C / 6°C | 6days (40 mm) Good | 11h Excellent | 63% Muggy | 6.5 High | Good | View Details |
| May best | 27°C / 12°C | 26°C / 11°C | 4days (31 mm) Good | 12.6h Excellent | 56% Moderate | 7.9 Very High | Excellent | View Details |
| June best | 33°C / 17°C | 33°C / 16°C | 1days (4 mm) Excellent | 13.5h Excellent | 44% Moderate | 8.2 Very High | Excellent | View Details |
| July | 37°C / 20°C | 37°C / 20°C | 0days (1 mm) Excellent | 13.5h Excellent | 39% Comfortable | 8.3 Very High | Good | View Details |
| August | 36°C / 20°C | 36°C / 21°C | 1days (2 mm) Excellent | 12.6h Excellent | 42% Moderate | 7.6 Very High | Good | View Details |
| September best | 32°C / 17°C | 31°C / 17°C | 2days (11 mm) Excellent | 11.3h Excellent | 47% Moderate | 6.4 High | Excellent | View Details |
| October best | 26°C / 13°C | 24°C / 11°C | 4days (44 mm) Good | 9.4h Good | 51% Moderate | 4.8 Moderate | Excellent | View Details |
| November | 18°C / 8°C | 16°C / 6°C | 7days (86 mm) Good | 7.7h Good | 66% Muggy | 3.2 Moderate | Good | View Details |
| December | 14°C / 5°C | 12°C / 2°C | 10days (136 mm) Wet | 6.1h Fair | 74% Muggy | 2.3 Moderate | Fair | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Clearlake are May, June, September, October, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Clearlake, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Clearlake is July, with average daytime highs of 37°C (98°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Clearlake is January, with average overnight lows of 5°C (40°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Clearlake is January, averaging 166mm of precipitation across 11 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Clearlake runs through March, January, December, with the heaviest rainfall in March. Based on 10-year averages for Clearlake.
Clearlake receives approximately 121 sunshine hours per year. The sunniest month is June with around 14 hours. Based on climate data for Clearlake.
The least favorable months to visit Clearlake are January, February, March, December, primarily due to frequent rain. For the best conditions, consider May, June, September, October instead.
The annual average UV index in Clearlake is 6, classified as high. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Clearlake is 58%, classified as moderate. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Yes, Clearlake receives snow. Months with snowfall average 2 snow days and 4 cm (2 in) of accumulation, with about 2 frost days during winter.
Average wind speeds in Clearlake are 12 km/h (7 mph). The windiest month is March with peak winds reaching 13 km/h (8 mph) (gusts up to 41 km/h / 25 mph).
Clearlake averages 13 clear-sky days per month with overall cloud cover around 38%. The clearest skies occur in July.
The annual average dew point in Clearlake is 9°C (48°F), which feels dry and comfortable. Outdoor activities are comfortable year-round from a humidity standpoint.
Clearlake has a Hot-Summer Mediterranean climate, classified as Csa under the Köppen system. Temperate climates have mild winters and warm summers, with rainfall spread across the year and four distinct seasons.
The 'feels like' temperature in Clearlake ranges from 10°C (50°F) to 23°C (73°F) on average. The 'feels like' temperature closely matches the actual temperature throughout most of the year.
Yes, June is a great time to visit Clearlake. It earns a climate score of 9.3/10 with Excellent.
For June in Clearlake, pack Breathable clothing, Sunscreen (SPF 30+), Sun hat, Sunglasses, Sandals. With average highs of 33°C (91°F) and 1 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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