Monthly climate guide
London weather in September
September in London is typically mild, with average daytime highs around 20°C (68°F) and night-time lows near 10°C (50°F). The month usually brings about 46 mm of rain (fairly dry) and is often cloudy. Daytime highs are 2°C cooler than August and 4°C warmer than October.
What stands out in September
- Skies are at their clearest this time of year.
- Comfortable temperatures make it easy to walk between Tower of London and British Museum.
- Just 110 km apart, but London runs about 2°C warmer than Dover this month.
- In London, September is early autumn.
Avg high
20°C
68°F
Avg low
10°C
50°F
Rainfall
46 mm
fairly dry
Humidity
80%
relative
Sky
65%
cloud · often cloudy
London weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 7°C / 45°F | 2°C / 35°F | 67 mm | 93% | 73% |
| February | 8°C / 46°F | 2°C / 35°F | 51 mm | 90% | 73% |
| March | 11°C / 51°F | 3°C / 37°F | 48 mm | 85% | 71% |
| April | 14°C / 57°F | 4°C / 40°F | 42 mm | 81% | 66% |
| May | 17°C / 63°F | 7°C / 45°F | 50 mm | 78% | 69% |
| June | 20°C / 68°F | 10°C / 51°F | 66 mm | 78% | 72% |
| July | 23°C / 73°F | 12°C / 54°F | 57 mm | 75% | 67% |
| August | 22°C / 72°F | 12°C / 54°F | 66 mm | 77% | 72% |
| September | 20°C / 68°F | 10°C / 50°F | 46 mm | 80% | 65% |
| October | 15°C / 60°F | 8°C / 46°F | 75 mm | 87% | 72% |
| November | 11°C / 51°F | 5°C / 40°F | 71 mm | 92% | 74% |
| December | 8°C / 47°F | 3°C / 38°F | 83 mm | 94% | 75% |
What to pack for September
- T-shirts plus a light layer for the evening
- Comfortable trainers or sandals for long walks
- A small travel umbrella, just in case
Is September a good time to visit London?
Our London guide recommends: May to September for the warmest, driest weather and the longest daylight hours.
Many of London's biggest museums — including the British Museum — are free to enter, though special exhibitions carry a charge.
Best time to visit London →Other United Kingdom cities in September
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London weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/uk/london/september
<a href="https://weathercompare.eu/weather/uk/london/september">London weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/uk/london" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="London weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/uk/london/september">London weather in September</a> – WeatherCompare</p>
London in September: quick answers
Is September a good time to visit London?
Yes. September is one of the best months for London, with highs around 20°C and about 46 mm of rain.
How warm is London in September?
Average highs are about 20°C (68°F) and average lows about 10°C (50°F), based on 10 years of daily data.
Does it rain a lot in London in September?
London typically gets around 46 mm of rain in September — fairly dry.
When is the best time to visit London?
May to September for the warmest, driest weather and the longest daylight hours.
Figures are long-term averages for the area around London (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.