Bellingham weather in May

In May, Bellingham sees average daytime highs of 57°F and overnight lows near 48°F, with 3.4 in of rain across 11.3 wet days and about 15 hours of daylight. It is the 5th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 55°F in the first days to 59°F by the end. The sky is clear or mostly clear about 25% of the time in May, and the air most often feels dry.

Daylight stretches from about 14 h 18 min at the start of May to 15 h 36 min by month's end. Set against the rest of the year, May is Bellingham's 5th-clearest and 9th-windiest month. For the whole year in context, see Bellingham's year-round climate.

Daytime high
57°
5th warmest
Overnight low
48°
8th coldest
Rainfall
3.4 in
11.3 wet days
Daylight
15 hours
4:35 AM – 7:37 PM
Cloud cover
63%
5th clearest
Wind
5 mph
9th windiest
Solar energy
5.71 kWh/m²
Travel score
4.0
out of 10

Bellingham is city in, and the county seat of, Whatcom County in the State of Washington, United States.

Density
1,084/km²
people per km²
Founded
1852

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 55°F in the first days to 59°F by the end.

A typical May day in Bellingham reaches about 57°F in the afternoon and slips back to 48°F overnight — a 9°F spread between the day's warmth and the night's chill. On most days the high lands between 52°F and 64°F. Set against its neighbours, May runs about 5°F warmer than April and about 4°F cooler than June.

40°50°60°70°151015202531
Avg high (°F)Avg low (°F)
15546
25546
35546
45646
55646
65646
75647
85647
95647
105747
115747
125747
135748
145748
155748
165848
175849
185849
195849
205849
215849
225849
235850
245950
255950
265950
275950
285950
295951
305951
315951

How May really feels in Bellingham

Once humidity and wind are folded in, May averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Bellingham weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan44° / 38°8.418.63.28.50.6
Feb46° / 38°5.415.32.89.81.0
Mar49° / 40°6.718.91.911.61.5
Apr53° / 43°4.815.20.113.42.5
May57° / 48°3.411.30154.0
Jun61° / 53°2.59.4015.95.2
Jul66° / 57°1.35.1015.57.1
Aug67° / 58°1.85.3014.27.2
Sep64° / 54°3.29.1012.45.9
Oct56° / 48°6.414.7010.53.3
Nov48° / 41°9.518.81.191.4
Dec44° / 38°8.118.33.38.10.5

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% 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 59%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24357
34258
44357
54456
64456
74456
84357
94456
104555
114456
124456
134456
144357
154258
164258
174159
184159
194060
204060
213961
224060
234060
243961
253862
263961
273961
283862
293862
303961
313961

Chance of precipitation in May

Any precipitation

Bellingham gets around 3.4 in of rain over 11.3 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 36% and peaks near 43% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
143
242
341
440
539
638
738
837
936
1036
1135
1234
1334
1434
1534
1634
1734
1834
1934
2034
2135
2235
2335
2436
2536
2636
2736
2836
2937
3037
3137

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 99% 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
131000
14991
15991
16991
17991
18991
19991
20991
21991
22991
23991
24982
25982
26982
27982
28973
29973
30973
31973

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 14 h 18 min at the start of May to 15 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 78 minutes over May. Sunrise moves from 4:59 AM to 4:19 AM, and sunset from 7:16 PM to 7:55 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.34:597:16
214.34:577:17
314.44:557:19
414.44:537:20
514.54:527:22
614.64:507:23
714.64:487:25
814.74:477:26
914.74:457:27
1014.84:447:29
1114.84:427:30
1214.84:417:32
1314.94:397:33
1414.94:387:34
1515.04:377:36
1615.04:357:37
1715.14:347:39
1815.14:337:40
1915.24:317:41
2015.24:307:42
2115.24:297:44
2215.34:287:45
2315.34:277:46
2415.44:267:47
2515.44:257:49
2615.44:247:50
2715.54:237:51
2815.54:227:52
2915.54:217:53
3015.64:207:54
3115.64:197:55

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.71 kWh/m².

For context, solar energy here swings from a low near 0.84 kWh/m² to a high of 6.56 kWh/m² in July across the year — May's 5.71 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.5Bright
45.5Bright
55.5Bright
65.6Bright
75.6Bright
85.6Bright
95.7Bright
105.7Bright
115.7Bright
125.7Bright
135.7Bright
145.7Bright
155.7Bright
165.7Bright
175.7Bright
185.7Bright
195.7Bright
205.7Bright
215.7Bright
225.7Bright
235.7Bright
245.7Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
315.8Bright
Planning a trip in May

Hazard calendar for Bellingham

In seasonPeak

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

Bellingham's rainy season runs October–April, 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 Bellingham?

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

4.0
Sightseeing
5th-best month of the year
0.0
Beach & pool
6th-best month of the year

May is a reasonable time to visit Bellingham for sightseeing.

What to pack for Bellingham in May

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

In May, Bellingham sees daytime highs around 57°F and nights near 48°F. Worth packing: a warm layer, rain gear and sun protection. About 11 days see rain.

a warm layerrain gearsun protection

Sea temperature near Bellingham in May

The nearest coast averages about 53°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 19 mi away) is warmest in August at about 60°F and coldest in January near 45°F.

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

45°50°55°60°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°F)Comfort
Jan45Bracing
Feb45Bracing
Mar46Bracing
Apr49Bracing
May53Bracing
Jun56Bracing
Jul59Cool
Aug60Cool
Sep57Bracing
Oct52Bracing
Nov49Bracing
Dec46Bracing

UV index in Bellingham in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Bellingham peaks around July 17 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 17 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 17UV 8Dec 17UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar4Moderate
Apr4Moderate
May7High
Jun6High
Jul8Very high
Aug6High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Bellingham 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 Bellingham is worst in September — around 18 µg/m³ PM2.5 (moderate), about 3.2× the cleanest month (December, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1018 µg/m³Dec 176 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb9Good
Mar12Good
Apr12Good
May12Good
Jun11Good
Jul11Good
Aug18Moderate
Sep18Moderate
Oct12Good
Nov7Good
Dec6Good
Location & terrain

Where is Bellingham?

Bellingham sits at 48.8°N, 122.5°W, 69 ft above sea level, in United States. The nearest listed city is Anacortes, 18 mi away.

Topography around Bellingham

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

Within 2 miles, the terrain around Bellingham has only modest variations in elevation — a maximum elevation change of 666 ft around an average of 102 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,097 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 10,758 ft.

The land around Bellingham is covered by trees (39%), artificial surfaces (29%) and water (23%) within 2 miles, trees (49%) and water (26%) within 10 miles, and trees (51%) and water (32%) within 50 miles.

2 miles
666 ft
10 miles
3,097 ft
50 miles
10,758 ft
treesgrasslandcroplandartificial surfacesbare terrainsnow and icewater
May weather nearby: Anacortes 18 mi · Townline 22 mi · White Rock 23 mi · Abbotsford 23 mi · South Surrey 24 mi · Mount Vernon 24 mi · Langley 25 mi · Cloverdale 27 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 Bellingham (48.7595°, -122.4882°, elevation 69 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).