Updated 4 Aug 2026 · recomputed nightly
Visiting London in September 2026?
September sits between the seasons in London: mild and wet, around 21°C / 69°F with rain on about 10 days, Lively every day.
In short, a solid middle-ground pick.
Among the 12 months we forecast for London, September ranks 6th for crowd pressure. Its heaviest day is Mon 7 Sep, busier than 64% of the year; its lightest is Wed 16 Sep at 58%.
Preparing pays off in a month like this: timed-entry tickets and pre-booked tours turn the queue time into sightseeing time. see the options →
How busy is London in September?
It's quiet right through September — no crowded stretch to plan around.
The month barely moves — every day lands between 58% and 64% of the year. Daylight runs about 12 hours.
Either side of it, August picks up and October picks up.
The calmest days include the 16th, 17th and 18th — 14 days share that level, so there is room to choose.
September weather in London
Comfortably warm — around 21°C / 69°F, easy shirtsleeve weather, with rain on about 10 days, so keep a layer handy.
- London gets rain on about 10 days in September, so the odds of being caught out are real. What earns its bag space is a shell that packs to nothing, dries fast and has a hood that survives wind; a heavy waterproof is overkill and an umbrella is one more thing to carry through crowds. Browse on Amazon ↗
As an Amazon Associate, this site earns from qualifying purchases — we link categories, never specific products we haven't tested.
Is September worth it in London?
A fair balance — decent weather, crowds you can work around.
Worth booking the marquee sights ahead for the busy days, but you can keep the rest of the trip flexible.
Keep planning
Built on: UK's public holidays · school vacations across France and Germany · the official overseas-visits pattern (ONS, measured 2021–2023; UK national curve) · five years of weather records (2019–2023) · operator-confirmed events
Every figure is recomputed nightly from public and school holidays, and long-run climate normals. Gaps are shown, not filled.
