London · Month comparison
September vs May
May ranks #1 overall vs September at #4. Chelsea Flower Show, warm parks, 18°C — London at its most seductive before summer prices arrive.
September
#4 of 12 months
Best match
London's best-kept secret — 20°C, schools back, crowds thin, and the autumn cultural season opens.
- ↑Schools return in September — family tourist crowds evaporate almost overnight after the August bank holiday
- ↑London Design Festival, Totally Thames, and the full Southbank autumn programme make the cultural calendar excellent
May
#1 of 12 months
Best match
Chelsea Flower Show, warm parks, 18°C — London at its most seductive before summer prices arrive.
- ↑Chelsea Flower Show (third week of May): world-famous garden event with real local excitement around it
- ↑Royal Parks in full green: Londoners picnic in Hyde Park, Regent's Park, and Hampstead Heath in earnest
| Factor | September | May |
|---|---|---|
| Weather score | 7 | 8 |
| Value score | 5 | 6 |
| Crowd score | 6 | 6 |
| Events score | 7 | 8 |
| Atmosphere | 8 | 8 |
| Avg high temp | 20°C | 18°C |
| Monthly rain | 55mm | 49mm |
| Daily sunshine | 4.9hrs | 6.4hrs |
September trade-offs
- ↓Sunshine drops to 4.9 hours — the days noticeably shorter from August; evenings cool more quickly
- ↓Prices remain 30–40% above winter rates while the city transitions out of peak season
- ↓The Proms (BBC) at Royal Albert Hall run through September — tickets in high demand for top concerts
May trade-offs
- ↓Prices climbing toward summer — a week at a 3-star central hotel costs noticeably more than March
- ↓Chelsea Flower Show week sees south-west London traffic disruption and accommodation pressure
- ↓Half-term (late May bank holiday) briefly crowding family attractions across the city
Scores compare months within London. Climate data: Open Meteo ERA5 30-year normals (1991–2020). Methodology →