Windsor weather in May

In May, Windsor sees average daytime highs of 73°F and overnight lows near 51°F, with 1.1 in of rain across 3.6 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 71°F in the first days to 76°F by the end. The sky is clear or mostly clear about 56% 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 Windsor's 6th-clearest and 1st-windiest month. For the whole year in context, see Windsor's year-round climate.

Daytime high
73°
6th warmest
Overnight low
51°
8th coldest
Rainfall
1.1 in
3.6 wet days
Daylight
14 h 06 min
5:05 AM – 7:10 PM
Cloud cover
38%
6th clearest
Wind
5 mph
1st windiest
Solar energy
7.22 kWh/m²
Travel score
8.2
out of 10

Windsor is town in Sonoma County, California, United States.

Density
1,454/km²
people per km²
Founded
1992

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 71°F in the first days to 76°F by the end.

A typical May day in Windsor reaches about 73°F in the afternoon and slips back to 51°F overnight — a 22°F spread between the day's warmth and the night's chill. On most days the high lands between 62°F and 85°F. Set against its neighbours, May runs about 6°F warmer than April and about 7°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
17149
27149
37149
47149
57249
67249
77249
87250
97250
107250
117250
127250
137350
147350
157351
167351
177351
187351
197351
207451
217451
227452
237452
247452
257552
267552
277552
287553
297653
307653
317653

Windsor 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 daysDaylight (hours)Travel score
Jan57° / 40°5.710.39.64.0
Feb60° / 42°5.89.310.54.7
Mar63° / 44°4.49.511.75.7
Apr67° / 46°1.95.6137.0
May73° / 51°1.13.614.18.2
Jun80° / 55°0.31.214.68.5
Jul83° / 57°0.00.114.47.8
Aug83° / 57°0.00.213.57.8
Sep81° / 55°0.10.612.38.6
Oct74° / 50°1.43.2118.5
Nov63° / 44°3.06.29.96.2
Dec56° / 39°5.910.19.43.9

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 56% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 15% of May, with mostly cloudy or overcast conditions the remaining 28%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16535
26733
36733
46733
56733
66733
76733
86733
96733
106832
116931
126931
136931
147129
157129
167129
177228
187327
197327
207426
217426
227426
237624
247624
257624
267723
277723
287723
297723
307723
317723

Chance of precipitation in May

Any precipitation

Windsor gets around 1.1 in of rain over 3.6 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 11% and peaks near 14% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
114
213
313
413
513
613
713
813
913
1013
1113
1213
1312
1412
1512
1612
1712
1812
1911
2011
2111
2211
2310
2410
259
268
278
288
297
307
317

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 96% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
11991
12991
13991
14982
15982
16982
17982
18973
19973
20964
21964
22955
23955
24946
25937
26937
27928
28928
29919
30919
31919

Wind in May

Winds average 5 mph in May, the windiest month of the year.

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 5:21 AM to 4:55 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)
113.65:216:56
213.65:206:57
313.75:186:58
413.75:176:59
513.75:167:00
613.85:157:01
713.85:147:02
813.85:137:03
913.95:127:04
1013.95:117:05
1113.95:107:06
1214.05:097:07
1314.05:087:07
1414.05:077:08
1514.15:067:09
1614.15:057:10
1714.15:047:11
1814.15:037:12
1914.25:027:13
2014.25:027:14
2114.25:017:15
2214.35:007:15
2314.34:597:16
2414.34:597:17
2514.34:587:18
2614.44:577:19
2714.44:577:20
2814.44:567:20
2914.44:567:21
3014.44:557:22
3114.54:557:23

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 7.22 kWh/m².

For context, solar energy here swings from a low near 2.08 kWh/m² to a high of 8.01 kWh/m² in June across the year — May's 7.22 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
16.8Intense
26.9Intense
36.9Intense
46.9Intense
57.0Intense
67.0Intense
77.0Intense
87.0Intense
97.1Intense
107.1Intense
117.1Intense
127.1Intense
137.2Intense
147.2Intense
157.2Intense
167.2Intense
177.2Intense
187.3Intense
197.3Intense
207.3Intense
217.3Intense
227.3Intense
237.4Intense
247.4Intense
257.4Intense
267.5Intense
277.5Intense
287.5Intense
297.6Intense
307.6Intense
317.6Intense
Planning a trip in May

Hazard calendar for Windsor

In seasonPeak

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

Windsor'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 Windsor?

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

8.2
Sightseeing
4th-best month of the year
6.3
Beach & pool
6th-best month of the year

May is one of the better times to visit Windsor for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Windsor in May

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

In May, Windsor sees daytime highs around 73°F and nights near 51°F. Pack sun protection. Worth having: light clothes. About 4 days see rain.

sun protectionlight clothes

Sea temperature near Windsor in May

The nearest coast averages about 51°F in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 21 mi away) is warmest in September at about 55°F and coldest in May near 51°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

50°52°54°56°JanFebMarAprMayJunJulAugSepOctNovDecbracing
Sea temperature (°F)Comfort
Jan53Bracing
Feb53Bracing
Mar53Bracing
Apr51Bracing
May51Bracing
Jun51Bracing
Jul53Bracing
Aug54Bracing
Sep55Bracing
Oct55Bracing
Nov54Bracing
Dec53Bracing

UV index in Windsor 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 Windsor peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 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 17UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr6High
May9Very high
Jun10Extreme
Jul10Extreme
Aug9Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Low

Air quality in Windsor 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 Windsor is worst in September — around 24 µg/m³ PM2.5 (moderate), about 4.1× the cleanest month (June, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1623 µg/m³Jun 116 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar9Good
Apr7Good
May7Good
Jun6Good
Jul9Good
Aug17Moderate
Sep24Moderate
Oct16Moderate
Nov9Good
Dec7Good
Location & terrain

Where is Windsor?

Windsor sits at 38.5°N, 122.8°W, 118 ft above sea level, in United States. The nearest listed city is Santa Rosa, 9.3 mi away.

Topography around Windsor

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

Within 2 miles, the terrain around Windsor has only modest variations in elevation — a maximum elevation change of 476 ft around an average of 144 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 1,969 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 6,266 ft.

The land around Windsor is covered by trees (35%), artificial surfaces (28%) and grassland (26%) within 2 miles, trees (57%) and grassland (27%) within 10 miles, and trees (42%), grassland (27%) and water (24%) within 50 miles.

2 miles
476 ft
10 miles
1,969 ft
50 miles
6,266 ft
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Santa Rosa 9.3 mi · Rohnert Park 16 mi · Agua Caliente 24 mi · Petaluma 24 mi · Clearlake 30 mi · Novato 33 mi · Napa 34 mi · American Canyon 40 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 Windsor (38.5471°, -122.8164°, elevation 118 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).