London in September
In September, London averages 20°C (68°F) during the day and 13°C (55°F) at night, with around 8 days of rain (49 mm total).
High seasonConditions are comfortable for sightseeing without being sweltering. Occasional showers are likely but won't dominate.
September is a great month to visit London: pleasant temperatures and relatively few wet days.
How September compares to the rest of the year in London
September is in the middle of the year for warmth in London (4th of 12) and one of the driest months (12th of 12). Daytime temperature runs 5°C above the annual average (16°C). September runs 3°C cooler than August (23°C) and cools 4°C in October (16°C).
September sunrise & sunset in London
Times shown for London local time (Europe/London), calculated for the 15th of September. They shift by a few minutes day to day across the month.
Photography light in London — September
Golden-hour and blue-hour windows for the 15th of September, in London's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).
📅 When to book — London in September
Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on September's tier (High season) and London's popularity.
Crowds & pricing — September in London
This is a busy month in London — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.
Why this tier: excellent tourism weather
Sun & mosquito risk — September in London
UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.
London in other months
| Month | Avg high | Avg low | Rainfall | Rain days | Snow days |
|---|---|---|---|---|---|
| January | 8°C / 46°F | 3°C / 37°F | 55 mm | 11 | 2 |
| February | 9°C / 48°F | 3°C / 37°F | 41 mm | 9 | 2 |
| March | 12°C / 54°F | 5°C / 41°F | 42 mm | 9 | 1 |
| April | 15°C / 59°F | 7°C / 45°F | 44 mm | 9 | 0 |
| May | 18°C / 64°F | 10°C / 50°F | 49 mm | 9 | 0 |
| June | 22°C / 72°F | 13°C / 55°F | 45 mm | 8 | 0 |
| July | 24°C / 75°F | 15°C / 59°F | 45 mm | 8 | 0 |
| August | 23°C / 73°F | 15°C / 59°F | 50 mm | 8 | 0 |
| September | 20°C / 68°F | 13°C / 55°F | 49 mm | 8 | 0 |
| October | 16°C / 61°F | 10°C / 50°F | 69 mm | 10 | 0 |
| November | 11°C / 52°F | 6°C / 43°F | 59 mm | 11 | 1 |
| December | 8°C / 46°F | 3°C / 37°F | 55 mm | 11 | 2 |
Other cities with similar September weather
🌍 See the full ranked list of climate twins for London in September →
Frequently asked questions
How hot is London in September?
In September, London averages a high of 20°C (68°F) and a low of 13°C (55°F) — generally mild and pleasant.
Does it rain a lot in London in September?
September sees occasional rain in London, with about 8 rainy days on average.
Is September a good time to visit London?
September is mild and pleasant. It suits travelers who are comfortable with mild and pleasant weather; check the month-by-month ranking to compare it against the rest of the year.
What should I pack for London in September?
Pack light layers for warm days and cooler evenings. See the full September packing list for London for a complete, climate-based checklist.
Check the live 10-day forecast and sunrise/sunset.