August is the cheapest month to fly this route, with average fares around $940 round trip.
Average round-trip fares by departure month, based on current availability.
| Month | Avg Price | Lowest | Relative Cost | |
|---|---|---|---|---|
| May 2026 | $1088 | $980 | ||
| June 2026 | $1115 | $985 | Peak | |
| July 2026 | $1060 | $1009 | ||
| August 2026 | $940 | $885 | Best |
Departing on Tuesday offers the lowest average fares at $1035. Saturday departures are the most expensive at $1147, a difference of $112.
The best time to fly is August. Set up an alert and we'll notify you when prices drop.
Get Started Free →The cheapest month to fly from San Francisco to London is August, with average round-trip fares around $940. The lowest fare found in August is $885.
Tuesday departures are the cheapest, averaging $1035 round trip. The most expensive day is Saturday at $1147.
Based on current pricing trends, booking for August travel offers the best value. Avoid June if possible, as fares average $1115 compared to $940 in the cheapest month. May is a solid middle-ground option at $1088.
Flying in August instead of June can save you approximately $175 per round trip. The cheapest month averages $940 while the most expensive averages $1115.
Airlines, flight times, price calendar, and more for San Francisco to London
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