5-day weather forecast London Sep 21, 2026

23°13° · Sunny

Weather forecast London tomorrow Sep 21, 2026: sunny, temperature from 13 °C to 23 °C.

Precipitation probability 12%. Wind up to 2 m/s (gusts 2.94 m/s). Air humidity 30–59%, atmospheric pressure 773–775 mm Hg, UV index up to 3.9.

Sunrise 06:45
Sunset 19:01
Waxing Gibbous82% illuminated
Moonrise 17:25 · Moonset 00:38
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Table

Forecast from 13 °C to 23 °C and precipitation

Temperature & Precipitation
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Temperature (°C)151414141313131313151618192121222323222120201919
Precipitation (mm/hr)000000000000000000000000

Cloud cover and precipitation probability

Cloud cover & Rain chance
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Cloud cover (%)100618936925937671088896616536055825140000
Rain chance (%)1271151286931095144111222333

Wind speed and direction

Wind & Wind gust
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Wind (m/s)110.690.611.190.890.390.190.391.111.391.611.691.61221.691.311.190.810.890.890.50.61
Wind gust (m/s)1.221.110.810.721.611.030.420.190.641.7222.222.222.112.612.812.942.612.310.8311.110.50.69
Wind direction (°)NW 325°NNW 348°N 357°NNW 337°N 359°NNE 15°NNE 15°NNE 32°SSW 203°WSW 246°WSW 256°W 267°W 268°WNW 288°WNW 287°WNW 288°WNW 292°WNW 299°NW 305°WNW 295°NW 320°NNW 345°ENE 62°SSE 155°

Air humidity

Humidity
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Humidity (%)505153555658585956504539333030323438424851555859

Atmospheric pressure

Pressure
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Pressure (mm Hg)774774774774774774774774775775775774774774773773773773773773773773773773

Ultraviolet index

UV Index
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
UV Index000000000.20.81.72.43.63.93.62.81.70.80.200000

Air quality & pollen

Air quality
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
PM2.5 (µg/m³)8.99.310.210.310.710.41213.914.617.313.910.68.67.16.36.15.5555.67.99.811.211.5
PM10 (µg/m³)17.918.219.219.117.216.517.419.123.323.721.417.115.715.215.113.711.110.610.911.413.714.717.818.2
Ozone (O₃) (µg/m³)222021171615101621345263697175747267523218812
NO₂ (µg/m³)40.43935.3343635.535.840.644.443.444.427.919.217.416.613.515.116.718.728.442.653.161.964.3
SO₂ (µg/m³)1.92.12.22.42.82.2345.14.94.12.621.61.61.31.31.21.11.52.33.54.33.8
CO (µg/m³)238239229226242251265299331319297283250231224215208217206214225251262251

London on the map

Data Sources & Methodology

Our weather forecasts are powered by a professional weather data provider that aggregates data from national weather services, satellite observations, radar networks, and over 80,000 weather stations worldwide. Forecast data is updated multiple times daily. We convert raw data into clear summaries — wind speed in m/s, pressure in mmHg — so you can plan your day with confidence.