Clearlake weather in May

In May, Clearlake sees average daytime highs of 71°F and overnight lows near 51°F, with 1.4 in of rain across 4.7 wet days and about 14.1 hours of daylight. It is the 6th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 69°F in the first days to 75°F by the end. The sky is clear or mostly clear about 52% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 36 min at the start of May to 14 h 30 min by month's end. Set against the rest of the year, May is Clearlake's 6th-clearest and 2nd-windiest month. For the whole year in context, see Clearlake's year-round climate.

Daytime high
71°
6th warmest
Overnight low
51°
7th coldest
Rainfall
1.4 in
4.7 wet days
Daylight
14 h 06 min
5:03 AM – 7:10 PM
Cloud cover
41%
6th clearest
Wind
5 mph
2nd windiest
Solar energy
7.17 kWh/m²
Travel score
7.8
out of 10

Clearlake is city in Lake County, California, United States.

Density
554/km²
people per km²
Founded
1980

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 69°F in the first days to 75°F by the end.

A typical May day in Clearlake reaches about 71°F in the afternoon and slips back to 51°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 59°F and 83°F. Set against its neighbours, May runs about 8°F warmer than April and about 9°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
16848
26949
36949
46949
56949
66949
76949
87050
97050
107050
117050
127050
137151
147151
157151
167151
177151
187151
197252
207252
217252
227352
237353
247353
257353
267453
277454
287454
297554
307554
317555

Clearlake weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan53° / 38°6.110.91.49.62.8
Feb55° / 40°5.99.41.710.53.6
Mar59° / 42°4.710.41.411.74.6
Apr64° / 45°2.16.50.3136.2
May71° / 51°1.44.7014.17.8
Jun80° / 58°0.52.1014.78.2
Jul87° / 64°0.00.2014.56.6
Aug86° / 63°0.10.4013.56.7
Sep82° / 59°0.21012.38.2
Oct72° / 52°1.63.80118.2
Nov60° / 43°3.27.10.29.95.1
Dec52° / 38°6.210.50.89.32.8

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 52% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 32%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16238
26238
36337
46337
56337
66436
76436
86436
96436
106535
116634
126634
136634
146733
156733
166931
176931
186931
196931
207030
217030
227030
237129
247129
257228
267327
277327
287327
297327
307327
317327

Chance of precipitation in May

Any precipitation

Clearlake gets around 1.4 in of rain over 4.7 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 15% and peaks near 16% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
116
216
315
415
515
615
715
815
915
1015
1115
1215
1315
1415
1516
1616
1716
1816
1916
2016
2116
2216
2315
2415
2514
2614
2713
2812
2912
3011
3111

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the dry band about 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
11000
21000
31000
41000
51000
61000
71000
81000
91000
101000
111000
121000
13991
14991
15991
16991
17991
18991
19991
20982
21982
22982
23982
24973
25973
26964
27964
28964
29955
30955
31955

Wind in May

Winds average 5 mph in May.

Across May, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 36 min at the start of May to 14 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 54 minutes over May. Sunrise moves from 5:19 AM to 4:53 AM, and sunset from 6:56 PM to 7:23 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.65:196:56
213.65:186:57
313.75:176:58
413.75:166:59
513.85:157:00
613.85:137:01
713.85:127:02
813.95:117:03
913.95:107:04
1013.95:097:05
1114.05:087:06
1214.05:077:07
1314.05:067:08
1414.15:057:09
1514.15:047:09
1614.15:037:10
1714.25:027:11
1814.25:017:12
1914.25:017:13
2014.25:007:14
2114.34:597:15
2214.34:587:16
2314.34:577:17
2414.34:577:17
2514.44:567:18
2614.44:567:19
2714.44:557:20
2814.44:547:21
2914.54:547:21
3014.54:537:22
3114.54:537:23

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 7.17 kWh/m².

For context, solar energy here swings from a low near 2.01 kWh/m² to a high of 8.26 kWh/m² in July across the year — May's 7.17 kWh/m² falls in the middle.

02468151015202531
Solar energy (kWh/m²)Level
16.8Intense
26.8Intense
36.8Intense
46.9Intense
56.9Intense
66.9Intense
77.0Intense
87.0Intense
97.0Intense
107.0Intense
117.0Intense
127.1Intense
137.1Intense
147.1Intense
157.1Intense
167.2Intense
177.2Intense
187.2Intense
197.2Intense
207.3Intense
217.3Intense
227.3Intense
237.3Intense
247.4Intense
257.4Intense
267.5Intense
277.5Intense
287.5Intense
297.6Intense
307.6Intense
317.6Intense
Planning a trip in May

Hazard calendar for Clearlake

In seasonPeak

None of Clearlake's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Clearlake's rainy season runs November–March, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit Clearlake?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.8
Sightseeing
4th-best month of the year
5.3
Beach & pool
6th-best month of the year

May is one of the better times to visit Clearlake for general sightseeing.

What to pack for Clearlake in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Clearlake sees daytime highs around 71°F and nights near 51°F. Pack sun protection. About 5 days see rain.

sun protection

UV index in Clearlake in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Clearlake peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 10Dec 15UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar5Moderate
Apr6High
May9Very high
Jun10Extreme
Jul10Extreme
Aug9Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Low

Air quality in Clearlake in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Clearlake is worst in September — around 31 µg/m³ PM2.5 (moderate), about 5.8× the cleanest month (June, 5 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1031 µg/m³Jun 106 µg/m³
PM2.5 (µg/m³)Level
Jan6Good
Feb8Good
Mar9Good
Apr8Good
May6Good
Jun5Good
Jul14Moderate
Aug29Moderate
Sep31Moderate
Oct14Moderate
Nov8Good
Dec6Good
Location & terrain

Where is Clearlake?

Clearlake sits at 39.0°N, 122.6°W, 1,417 ft above sea level, in United States. The nearest listed city is Windsor, 30 mi away.

Topography around Clearlake

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Clearlake.

Within 2 miles, the terrain around Clearlake has significant variations in elevation — a maximum elevation change of 853 ft around an average of 1,493 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,409 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 6,982 ft.

The land around Clearlake is covered by trees (39%) and grassland (28%) within 2 miles, trees (52%) and grassland (38%) within 10 miles, and trees (52%) and grassland (30%) within 50 miles.

2 miles
853 ft
10 miles
3,409 ft
50 miles
6,982 ft
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Windsor 30 mi · Ukiah 34 mi · Santa Rosa 36 mi · Rohnert Park 43 mi · Agua Caliente 45 mi · Napa 49 mi · Woodland 50 mi · Petaluma 50 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Clearlake (38.9582°, -122.6264°, elevation 1,417 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).