London weather in August

In August, London sees average daytime highs of 25°C and overnight lows near 15°C, with 84 mm of rain across 10.6 wet days and about 13.8 hours of daylight. It is the 2nd-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 25°C through the month. The sky is clear or mostly clear about 33% of the time in August, and the air most often feels comfortable.

Daylight stretches from about 14 h 24 min at the start of August to 13 h 06 min by month's end. Set against the rest of the year, August is London's 3rd-clearest and 12th-windiest month. For the whole year in context, see London's year-round climate.

Daytime high
25°
2nd warmest
Overnight low
15°
11th coldest
Rainfall
84 mm
10.6 wet days
Daylight
13 h 48 min
5:36 AM – 7:22 PM
Cloud cover
55%
3rd clearest
Wind
10 km/h
12th windiest
Solar energy
5.55 kWh/m²
Travel score
6.8
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 August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 25°C through the month.

A typical August day in London reaches about 25°C in the afternoon and slips back to 15°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 21°C and 29°C. Set against its neighbours, August runs about 1°C cooler than July and about 4°C warmer than September.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12616
22616
32616
42616
52616
62616
72616
82516
92515
102515
112515
122515
132515
142515
152515
162515
172515
182515
192515
202515
212515
222515
232515
242515
252515
262515
272414
282414
292414
302414
312414

How August really feels in London

Once humidity and wind are folded in, August 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

August 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 August compares with the rest of the year at a glance. August is the 2nd-warmest and 7th-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 August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 23% of August, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15644
25644
35644
45644
55644
65644
75545
85644
95644
105644
115545
125644
135743
145743
155743
165743
175644
185644
195743
205644
215644
225644
235644
245644
255743
265743
275644
285644
295743
305644
315644

Chance of precipitation in August

Any precipitation

London gets around 84 mm of rain over 10.6 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 35% and peaks near 39% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
139
238
338
438
537
637
737
837
937
1037
1136
1236
1336
1436
1536
1635
1735
1835
1934
2034
2133
2233
2333
2432
2532
2631
2731
2831
2931
3031
3132

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the comfortable band about 28% of days. Sticky, muggy-or-worse air turns up on roughly 22% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1212728195
2222728195
3222727194
4222727194
5222727194
6232726194
7232726194
8242726194
9242725194
10252725194
11252725184
12252825184
13252825184
14252825174
15252826174
16252926174
17252926174
18252926173
19252926173
20252926173
21252925183
22252925183
23262924183
24262924183
25272923183
26282822192
27292822192
28302821182
29322820182
30322720183
31342719183

Wind in August

Winds average 10 km/h in August, the calmest month.

Across August, daily wind ranges from about 10 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2911calm
3011calm
3111calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 24 min at the start of August to 13 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over August. Sunrise moves from 5:19 AM to 5:53 AM, and sunset from 7:42 PM to 6:57 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.45:197:42
214.35:217:41
314.35:227:40
414.35:237:39
514.25:247:38
614.25:257:36
714.25:267:35
814.15:277:34
914.15:287:32
1014.05:297:31
1114.05:307:30
1213.95:317:28
1313.95:337:27
1413.95:347:25
1513.85:357:24
1613.85:367:22
1713.75:377:21
1813.75:387:19
1913.65:397:18
2013.65:407:16
2113.55:417:14
2213.55:437:13
2313.55:447:11
2413.45:457:09
2513.45:467:08
2613.35:477:06
2713.35:487:04
2813.25:497:03
2913.25:507:01
3013.15:526:59
3113.15:536:57

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.55 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 — August's 5.55 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.0Intense
26.0Bright
36.0Bright
45.9Bright
55.9Bright
65.9Bright
75.8Bright
85.8Bright
95.8Bright
105.7Bright
115.7Bright
125.7Bright
135.6Bright
145.6Bright
155.6Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.4Bright
215.4Bright
225.3Bright
235.3Bright
245.3Bright
255.2Bright
265.2Bright
275.2Bright
285.1Bright
295.1Bright
305.1Bright
315.0Bright
Planning a trip in August

Is August a good time to visit London?

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

6.8
Sightseeing
1st-best month of the year
6.1
Beach & pool
2nd-best month of the year

August is a reasonable time to visit London for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for London in August

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

In August, London sees daytime highs around 25°C and nights near 15°C. Worth packing: light clothes, rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

Sea temperature near London in August

The nearest coast averages about 23°C in August — 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 August

LowModerateHighVery highExtreme

Clear-sky midday UV in August 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
August 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).