Cheap flights from London to San Francisco from €422

The cheapest month to fly to San Francisco from London is in February. Flight prices, which tend to average around €474, are often lower during this time because this is during the off-season. If you aren’t able to travel during the month of February, then book flights to San Francisco from London during September instead. Flights to San Francisco in September, while not as cheap as those in February, still average around €494.

On average, the least expensive day to fly to San Francisco from London is on a Thursday. momondo users have found tickets for Thursday departures for as low as €678. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Wednesday is the most expensive day to depart from London because it is more convenient for both business and leisure travellers. As a result, prices tend to be around €1,142.

According to our data, the cheapest time of day to fly to San Francisco is in the morning. momondo users have found flights departing from London to San Francisco in the morning for as low as €619. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. If you have a flexible travel schedule, then try to avoid flying in the afternoon when prices are €1,142 on average. Flights to San Francisco from London in the afternoon are generally more expensive because this time of day is more convenient for travellers’ schedules.

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

You are more likely to see cheaper flights to San Francisco from London when booking weeks ahead of your departure date. In general, you can expect to find flights to San Francisco for around €586 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 for as low as €532 on momondo.

There is only 1 cabin class available to choose from on London to San Francisco flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 33% on your flight if you consider stops on a London to San Francisco flight.

As of March 2026, prices for London to San Francisco flights are approximately 2% more expensive when compared to flights at the same time last year.

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 143 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, Virgin Atlantic have had the fewest delays on this route over the last 12 months, with about 10% of their flights experiencing any sort of delay.

As of March 2026, there are 29 flights per day flying from London to San Francisco. The most common time of day flights depart is 11:00, with 58% of flights taking off at midday.

As of March 2026, there are 205 flights per week flying from London to San Francisco. The most common day of the week flights depart is Wed, with 15% of flights taking off on this day.