What September feels like in London
In London, September brings early autumn. Afternoons are mild and comfortable for most people in light layers. The gap between afternoon and night is small, so nights are cool and the temperature hardly changes after dark. Humidity is on the high side, but mild temperatures keep it comfortable.
Rain in London in September
It is a changeable month: rain comes about one day in 3, with dry spells in between. A rainy day brings about 5.6 mm (0.2 in) on average — steady rain rather than a passing shower. Across the year London averages about 5.3 mm per rainy day, so September is typical. It is among the three driest months of the year.
Daylight and sunshine in September
In mid-September, sunrise is at about 6:34 am and sunset at about 7:18 pm (local time) — 12 h 44 min of daylight. Evenings are drawing in — 1 h 57 min less daylight than mid-August. About 65% of daylight hours are sunny; in short, there are plenty of bright spells.
How September compares to the rest of the year
Ranked by average high, September comes out as the 4th warmest month in London. Compared with August, afternoons are 2.3°C (4.1°F) cooler, with 9 mm less rain. Temperatures keep falling into October. The next month's average high: 15.3°C (59.5°F).
Who September suits
- Sightseeing: a good fit — daytime temperatures are fine for walking around.
- Parks & outdoor: a good fit — good conditions for sitting outside.
Tips for visiting London in September
Rain Protection
A compact umbrella and a light waterproof jacket.
Sunglasses
Frequent sunshine — sunglasses and a light hat.
Quick questions
How warm is London in September?
Afternoons average 19.2°C (66.6°F) and nights about 11.5°C (52.7°F) — mild by most people's standards. It is the 4th warmest month of the year.
Does it rain a lot in London in September?
It does: about 9 rainy days bring roughly 50 mm, so plan some indoor options.
What should I wear in London in September?
The numbers point to rain protection and sunglasses. Evenings feel similar to the day, so the same clothes work from morning to night.
Is September or October better for visiting London?
On our 12-month climate ranking, September comes out ahead (#1 of 12 vs #7). October is cooler and has more rainy days.