Cheap flights from London Heathrow Airport to San Francisco from £399

The month of February is, on average, the cheapest month to fly to San Francisco from London Heathrow Airport, with most prices found around £419. If you are unable to visit San Francisco during the month of February, then departing from London Heathrow Airport during the month September is also very affordable. Most momondo users find prices during this month for around £430.

The cheapest day to depart on your flight to San Francisco is on a Thursday when prices can be found for as low as £566. This is often the case because there is less demand to fly during this day of the week. Flights from London Heathrow Airport to San Francisco on a Sunday will generally be more expensive and average around £658. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

Our most recent data shows that the best time of day to fly to San Francisco is in the morning. Flights from London Heathrow Airport to San Francisco during this time can be as low as £567. Try not to purchase tickets at midday because they tend to be around £788. Of course, these prices can vary depending on the time of year and what airport you fly to.

Fly from London Heathrow to San Francisco for the best London Heathrow - San Francisco flight prices

You are more likely to see cheaper flights to San Francisco from London Heathrow Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to San Francisco for around £512 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to San Francisco from London Heathrow Airport for as low as £464 on momondo.

You could potentially save up to 2% on your flight if you consider stops on a London Heathrow Airport to San Francisco flight.

As of April 2026, prices for London Heathrow Airport to San Francisco flights are approximately 8% more expensive when compared to flights at the same time last year.

SWISS, United Airlines, and Austrian Airlines are the most popular carriers operating from London Heathrow to San Francisco

Virgin Atlantic, British Airways and Lufthansa are the top three most popular airlines that fly to San Francisco from London Heathrow Airport according to our data. Virgin Atlantic is the first choice among our users, with 40% of people opting to fly with this airline when travelling to San Francisco. Keep in mind that there are 18 different airlines that fly to San Francisco on a routine basis, so you have a few additional options to choose from.

Historically, on average around 11% of flights between London and San Francisco have experienced a delay on any given week. The average delay length over the past 12 months has been 147 minutes.

Generally, flights departing in the morning tend to experience fewer delays. Flights departing in the evening have, in the past, seen delays more frequently in comparison.

Tuesday is statistically the day of the week that experiences the fewest delays on this flight route. Wednesday has historically seen more delays on average compared to the rest of the week.

According to our data, United Airlines have had the fewest delays on this route over the last 12 months, with about 10% of their flights experiencing any sort of delay.

Dublin (DUB) was the most common stop: 51% of momondo users choosing one-stop flights on this route connected there.

Flights via Frankfurt am Main (FRA) offer the lowest average return price of £363.

Flights connecting via Frankfurt am Main (FRA) have the shortest average one-way travel time: 14h 10m.

Frankfurt am Main (FRA) has the shortest average stopover time for this route: 1h 23m.

As of April 2026, 35 flights take off from London Heathrow Airport and land in San Francisco each day. The most common flight departure time for this route is 10:00, with 55% of daily flights taking off in the afternoon.

247 flights are operational weekly from London Heathrow Airport to San Francisco as of April 2026. The most popular departure day for this route is Mon, with 17% of flights per week taking off on this day.