Weather in London in September 2025
Average weather
Average temperature in London in September
Going from a maximum of +90°F during the day to a minimum of +48°F during the night, the temperature in September averages around +73°F.
The average maximum temperature goes down 9% by the end of the month, compared with the beginning of the month, from +72°F to +68°F.
Is London warm or cold in September?
London is typically mild in September.
Maximum temperatures go down compared to the previous month from +72°F to +66°F. The minimum temperature also goes down from +57°F to +54°F.
Pack a light jacket as it will be warm in the day and cool in the evenings.
Take a look at how September is compared to other months in London:
Travel to London
Climate in London in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +72°F | +66°F | +59°F | ||||
| Min. temperature | ||||||
| +45°F | +37°F | +28°F | ||||
| Max. temperature | ||||||
| +99°F | +90°F | +82°F | ||||
| Rainfall | ||||||
| 58 mm | 47 mm | 68 mm | ||||
| Wind | ||||||
| 3 m/s | 3 m/s | 3 m/s | ||||
| Humidity | ||||||
| 70% | 74% | 78% | ||||
| Air pressure | ||||||
| 1014 HPa | 1015 HPa | 1013 HPa | ||||
| Sunny days | ||||||
| 5 | 4 | 4 | ||||
| Cloudy days | ||||||
| 9 | 11 | 11 | ||||
| Rainy days | ||||||
| 16 | 14 | 16 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as good as in August. It’s getting colder in September. From +72°F in the day, the average maximum temperature lowers to +66°F. As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 58 mm to 47 mm. Humidity rises from 70% to 74%. The average wind speed doesn’t change much during September, staying around 3 m/s. The days becoming less sunny, going from 5 sunny days in August to 4 in September.
Next month (October) brings a further decline in the weather.
Wind
The average wind speed is 3 m/s getting up to 6 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in London is gradually increasing during September, going from 2 m/s to 3 m/s over the course of the month.
Rain
How was the weather last September in London?
Climate Change Over the Years
The climate in London in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1979 (+54°F) and the highest in 2022 (+62°F). The driest year was 1996 with only 431 mm of rainfall, and the wettest year was 2021 with 1037 mm.
FAQ
Is September a good time to visit London?
Can you sunbathe in London in September?
Is London rainy in September?
Is it sunny in London in September?
How much does it cost to fly to London in September?
Other cities in United Kingdom
Monthly weather in London
Source of the data
For this page, we’ve looked at the typical weather in London, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.