London weather in May

In May, London sees average daytime highs of 19°C and overnight lows near 8°C, with 98 mm of rain across 12.5 wet days and about 14.4 hours of daylight. It is the 5th-warmest and 3rd-wettest month of the year here.

Highs climb over the month, from about 16°C in the first days to 21°C by the end. The sky is clear or mostly clear about 28% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 54 min at the start of May to 14 h 54 min by month's end. Set against the rest of the year, May is London's 5th-clearest and 8th-windiest month. For the whole year in context, see London's year-round climate.

Daytime high
19°
5th warmest
Overnight low
8th coldest
Rainfall
98 mm
12.5 wet days
Daylight
14 h 30 min
5:08 AM – 7:35 PM
Cloud cover
62%
5th clearest
Wind
12 km/h
8th windiest
Solar energy
6.05 kWh/m²
Travel score
5.6
out of 10

London is city in Southwestern Ontario, Canada.

Air quality
Good
PM2.5 7 µg/m³ · 2019
Density
1,004/km²
people per km²
Founded
1826

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 16°C in the first days to 21°C by the end.

A typical May day in London reaches about 19°C in the afternoon and slips back to 8°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 12°C and 26°C. Set against its neighbours, May runs about 6°C warmer than April and about 5°C cooler than June.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
1166
2166
3166
4166
5176
6177
7177
8177
9177
10187
11187
12188
13188
14188
15188
16198
17198
18199
19199
20209
21209
22209
232010
242010
252110
262110
272110
282111
292111
302211
312211

How May really feels in London

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

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
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.

London weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-1° / -8°7211.79.69.20.0
Feb-0° / -9°589.58.210.20.0
Mar / -4°7010.95.711.60.4
Apr12° / 9312.42.213.13.1
May19° / 9812.5014.45.6
Jun24° / 14°10212015.16.5
Jul26° / 16°10011.9014.86.5
Aug25° / 15°8410.6013.86.8
Sep21° / 11°869.7012.36.6
Oct14° / 8611.80.210.84.1
Nov / 7711.13.99.51.0
Dec / -5°6811.28.18.90.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% 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 56%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14159
24258
34159
44159
54258
64258
74258
84258
94258
104357
114357
124357
134357
144357
154357
164456
174555
184555
194456
204456
214456
224654
234654
244654
254654
264654
274654
284654
294555
304555
314555

Chance of precipitation in May

Any precipitation

London gets around 98 mm of rain over 12.5 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 40% and peaks near 42% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
142
242
342
442
542
642
742
842
942
1042
1142
1242
1342
1441
1541
1641
1741
1840
1940
2040
2139
2239
2339
2438
2538
2638
2738
2838
2938
3038
3138

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 83% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
196310
296310
394420
494420
594420
693430
792530
892530
991540
1090640
1190640
1289650
1388750
1488750
1586860
1685861
1784961
1883971
19811081
20811081
21781192
22781192
237512103
247412113
257412113
267113124
277113124
287014124
296814135
306715135
316715135

Wind in May

Winds average 12 km/h in May.

Across May, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1912light breeze
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912calm
3012calm
3112calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 54 min at the start of May to 14 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over May. Sunrise moves from 5:26 AM to 4:55 AM, and sunset from 7:18 PM to 7:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:267:18
213.95:257:19
313.95:247:20
414.05:227:21
514.05:217:23
614.15:197:24
714.15:187:25
814.25:177:26
914.25:167:27
1014.25:147:28
1114.35:137:29
1214.35:127:30
1314.35:117:32
1414.45:107:33
1514.45:097:34
1614.55:087:35
1714.55:067:36
1814.55:057:37
1914.65:047:38
2014.65:047:39
2114.65:037:40
2214.75:027:41
2314.75:017:42
2414.75:007:43
2514.74:597:44
2614.84:597:45
2714.84:587:46
2814.84:577:47
2914.94:567:48
3014.94:567:49
3114.94:557:49

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.05 kWh/m².

For context, solar energy here swings from a low near 1.32 kWh/m² to a high of 6.57 kWh/m² in June across the year — May's 6.05 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.6Bright
25.7Bright
35.7Bright
45.7Bright
55.8Bright
65.8Bright
75.8Bright
85.8Bright
95.9Bright
105.9Bright
115.9Bright
125.9Bright
136.0Bright
146.0Bright
156.0Intense
166.0Intense
176.1Intense
186.1Intense
196.1Intense
206.2Intense
216.2Intense
226.2Intense
236.2Intense
246.3Intense
256.3Intense
266.3Intense
276.3Intense
286.3Intense
296.3Intense
306.4Intense
316.4Intense
Planning a trip in May

Is May a good time to visit London?

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

5.6
Sightseeing
5th-best month of the year
2.3
Beach & pool
5th-best month of the year

May is a reasonable time to visit London for sightseeing.

What to pack for London in May

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

In May, London sees daytime highs around 19°C and nights near 8°C. Pack sun protection. Worth having: rain gear. About 13 days see rain.

sun protectionrain gear

Sea temperature near London in May

The nearest coast averages about 10°C 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 41 km away) is warmest in August at about 23°C and coldest in February near 1°C.

It's comfortable for a long swim from Jul 5 to Sep 20 — about 2.6 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan2Bracing
Feb1Bracing
Mar1Bracing
Apr4Bracing
May10Bracing
Jun17Cool
Jul22Refreshing
Aug23Refreshing
Sep21Refreshing
Oct16Cool
Nov10Bracing
Dec5Bracing

UV index in London 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 London peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 23UV 9Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr5High
May7High
Jun9Very high
Jul9Very high
Aug7High
Sep6High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is London?

London sits at 43.0°N, 81.2°W, 252 m above sea level, in Canada. The nearest listed city is St. Thomas, 24 km away.

Topography around London

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of London.

Within 3 km, the terrain around London has only modest variations in elevation — a maximum elevation change of 62 m around an average of 253 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 118 m; within 80 km, significant variations in elevation — a maximum elevation change of 271 m.

The land around London is covered by artificial surfaces (53%) and trees (36%) within 3 km, cropland (48%) and trees (24%) within 16 km, and cropland (57%) and water (22%) within 80 km.

3 km
62 m
16 km
118 m
80 km
271 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: St. Thomas 24 km · Strathroy 32 km · Woodstock 43 km · Tillsonburg 43 km · Stratford 48 km · Norfolk County 71 km · Brant 74 km · Forest Heights 75 km

Canada travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 83% of US
price level, 2025
GDP per capita
$55,698
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
2
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 53%none 35%Muslim 5%Hindu 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 London (42.9834°, -81.233°, elevation 252 m), 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).