Direct answer
The best time to visit London is late spring (May–June) and early autumn (September–early October) for mild weather, longer daylight, fewer crowds than peak summer, and good event options.
Why these months work best
- Weather: Temperatures are pleasant (about 12–22°C / 54–72°F), with lower chance of heavy rain than winter.
- Crowds: Fewer tourists than July–August, so shorter lines and easier reservations.
- Daylight: Longer days for sightseeing (especially May–June).
- Events: Major events like Chelsea Flower Show (May), RHS shows, and cultural festivals occur in spring; London Fashion Week and art openings happen in September.
When else to consider
- Summer (July–August): Best for festivals, open-air theatre, and warmest weather, but expect large crowds, sold-out attractions, and higher prices.
- Winter (November–February): Good for lower hotel rates, Christmas lights/markets, and ice rinks; cold, short days, and more rain. Boxing Day sales are a highlight for shoppers.
- Early spring (March–April): Cherry blossoms and gradually warming weather; variable conditions and some rain.
Budget and crowd tips
- To save money: Travel in late autumn (November, excluding Christmas/New Year) or January–February for lower fares and hotel deals.
- Avoid peak school holiday weeks (UK half-terms, late July–August, Easter week) if you want fewer crowds.
- Book attractions, West End shows, and restaurants in advance for summer and holiday periods.
Practical tips
- Pack layers and a light waterproof—London weather is changeable year-round.
- Use Oyster/Contactless or Travelcard for public transport savings.
- Check event calendars (Royal events, bank holidays) before finalizing dates—bank holidays can mean closures or increased crowding.
Quick summary
Choose May–June or September for the best overall balance of weather, crowds, and events. Pick winter or January for lower costs, and July–August for guaranteed warm weather and full event schedules.