London Weather in September
United Kingdom · Oceanic climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in London sees average temperatures ranging from a low of 12.1°C (53.8°F) to a high of 20.5°C (68.9°F), with a mean of 16.1°C (61.0°F). Compared to the annual average of 11.5°C (52.7°F), this month is 4.6°C warmer than the yearly norm. Precipitation averages 70.0mm, making it approximately 5.0mm wetter than the monthly average of 65.0mm. The city receives an average of 8.6 hours of sunshine per day during September, with relative humidity averaging 77.8%. Wind speeds reach an average maximum of 20.0 km/h. For travelers, this month offers a temperature experience in London, with wetter-than-average conditions compared to the rest of the year.
Having spent three winters in London, I can tell you the drizzle never really stops — it just changes intensity. The data says October is wettest, but honestly, it's the persistence rather than volume that gets you. May is my favorite: parks burst into bloom and you'll catch surprising stretches of sunshine between showers. The numbers say June-August is 'best,' but pack a light jacket regardless.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 18.4°C (65.1°F) | 16.1°C (61.0°F) | 12.6°C (54.7°F) |
| Rainfall | 48.7mm | 70.0mm | 106.6mm |
| Sunshine | 10.1 hrs | 8.6 hrs | 6.4 hrs |
| Humidity | 72.8% | 77.8% | 83.9% |
| Wind | 20.8 km/h | 20.0 km/h | 22.8 km/h |
| Rainy Days | 17.0 | 16.0 | 22.2 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting London in September, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in London in September?
The average temperature in London during September ranges from 12.1°C (53.8°F) to 20.5°C (68.9°F), with a mean of 16.1°C (61.0°F).
How much does it rain in London in September?
London receives an average of 70.0mm of precipitation in September, spread across approximately 16.0 rainy days.
What should I pack for London in September?
Based on September weather data, pack layers including light jackets and t-shirts, plus an umbrella.
Is September a good time to visit London?
September is a good time to visit London, with comfortable temperatures and manageable rainfall.
Other Months for London
Cities with Similar September Climate (Oceanic)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 51.51°, -0.13°. Timezone: Europe/London. Last updated: 2026-07-30.