London is the largest city in the United Kingdom, with about 9 million residents in Greater London. It is served by several airports, and Heathrow, Gatwick and Stansted are the three biggest. Visitors from the US need a UK Electronic Travel Authorisation before travelling.
Checking today’s fares with the airlines.
14 miles (23 km) from the city centre. 83.9 million passengers in 2024
| How | Route | Time |
|---|---|---|
| Train | Heathrow Express to Paddington (15 min from Terminals 2 and 3, 21 min from Terminal 5), every 15 minutes | about 15m |
| Train | Elizabeth line into central London, six trains per hour | about 35m |
| Metro | Piccadilly line Underground to central London (about 40-50 minutes) | about 40m |
30 miles (48 km) from the city centre. 43.2 million passengers in 2024
| How | Route | Time |
|---|---|---|
| Train | Gatwick Express non-stop to London Victoria, twice hourly | about 30m |
| Train | Southern and Thameslink trains to Victoria, London Bridge, Blackfriars and St Pancras (30 to 45 minutes) | about 45m |
31 miles (50 km) from the city centre. 29.7 million passengers in 2024
| How | Route | Time |
|---|---|---|
| Train | Stansted Express to Liverpool Street, every 15 minutes | about 48m |
US citizens need a passport and a UK Electronic Travel Authorisation (ETA) for visits of up to 6 months.
The ETA costs 20 pounds, is valid for 2 years or until the passport expires (whichever is sooner), and allows multiple visits. Apply through the UK ETA app or gov.uk/eta/apply; decisions usually arrive within a day but can take up to 3 working days. The UK is outside the Schengen Area, so EES and ETIAS do not apply.
Visit London's official tourism body describes June to September as peak season, with fewer crowds and lower prices in September to November and January to April. Rain falls year-round and October is statistically the wettest month.
Busiest: Jun-Sep. Quieter shoulder season: Jan-Apr, Sep-Nov.
| Month | Avg high | Avg low |
|---|---|---|
| Jan | 47°F (8°C) | 37°F (3°C) |
| Feb | 48°F (9°C) | 37°F (3°C) |
| Mar | 53°F (12°C) | 39°F (4°C) |
| Apr | 59°F (15°C) | 43°F (6°C) |
| May | 65°F (18°C) | 48°F (9°C) |
| Jun | 71°F (22°C) | 54°F (12°C) |
| Jul | 75°F (24°C) | 58°F (14°C) |
| Aug | 74°F (23°C) | 57°F (14°C) |
| Sep | 68°F (20°C) | 53°F (12°C) |
| Oct | 60°F (16°C) | 48°F (9°C) |
| Nov | 53°F (12°C) | 42°F (6°C) |
| Dec | 48°F (9°C) | 38°F (3°C) |
London is served by Heathrow Airport (LHR), Gatwick Airport (LGW) and Stansted Airport (STN). Heathrow Airport handled about 83.9 million passengers in 2024.
US citizens need a passport and a UK Electronic Travel Authorisation (ETA) for visits of up to 6 months. The ETA costs 20 pounds, is valid for 2 years or until the passport expires (whichever is sooner), and allows multiple visits. Apply through the UK ETA app or gov.uk/eta/apply; decisions usually arrive within a day but can take up to 3 working days. The UK is outside the Schengen Area, so EES and ETIAS do not apply.
Visit London's official tourism body describes June to September as peak season, with fewer crowds and lower prices in September to November and January to April. Rain falls year-round and October is statistically the wettest month.
Heathrow Express to Paddington (15 min from Terminals 2 and 3, 21 min from Terminal 5), every 15 minutes, about 15 minutes. Other options include elizabeth line into central london, six trains per hour and piccadilly line underground to central london.
Among the cities we cover, Boston (about 7h), New York (about 7h 10m), Washington, D.C. (about 7h 10m), Chicago (about 8h), Atlanta (about 8h 25m), Miami (about 9h 15m), Dallas (about 9h 20m), Seattle (about 9h 20m), Los Angeles (about 10h 20m) and San Francisco (about 10h 30m) have nonstop service to London as of October 2026.
London uses the pound sterling (GBP).
Information checked in October 2026. Schedules, fares and entry rules change, so confirm with the airline or the official source before you travel.