London weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Good
Best time to visit: May – September
What is the weather like in London in September?
In September, London is mild: daytime highs average 19 °C, and nights cool down to about 11 °C. Expect around 5 hours of sunshine a day. Rain falls on about 9 days, adding up to 44 mm. All in all, September is a good month for a holiday in London.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 77 | 77 | 52 |
| Day | 22° | 19° | 15° |
| Night | 14° | 11° | 9° |
| Sun | 6 h | 5 h | 4 h |
| Rain days | 10 | 9 | 11 |
More details for September
- Daylight
- 12 h 44 min06:34 – 19:18
- UV index
- 4 · moderateclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or more
- Wind
- 19 km/haverage daily peak
- Cloud cover
- 66 %on average
- Hot days
- 0 days30 °C or more
- Snow days
- 0 days1 cm or more of fresh snow
- Time zone
- UTC+1Europe/London
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %33 %
- Few rainy daysweight 30 %67 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Sunscreen
- A jumper for the evenings
- Rain jacket or umbrella
London in September: quick answers
Is London hot in September?
No. In September, London is mild: daytime highs average 19 °C and nights drop to about 11 °C.
Does it rain much in London in September?
Rain falls on about 9 days, adding up to 44 mm.
London month by month
The whole year in LondonAll destinations: United KingdomWhere to go in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, GeoNames (CC BY 4.0)