August is the cheapest month to fly this route, with average fares around $797 round trip.
Average round-trip fares by departure month, based on current availability.
| Month | Avg Price | Lowest | Relative Cost | |
|---|---|---|---|---|
| May 2026 | $840 | $780 | ||
| June 2026 | $895 | $719 | Peak | |
| July 2026 | $802 | $710 | ||
| August 2026 | $797 | $775 | Best |
Departing on Sunday offers the lowest average fares at $806. Friday departures are the most expensive at $896, a difference of $90.
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 Boston to London is August, with average round-trip fares around $797. The lowest fare found in August is $775.
Sunday departures are the cheapest, averaging $806 round trip. The most expensive day is Friday at $896.
Based on current pricing trends, booking for August travel offers the best value. Avoid June if possible, as fares average $895 compared to $797 in the cheapest month. May is a solid middle-ground option at $840.
Flying in August instead of June can save you approximately $98 per round trip. The cheapest month averages $797 while the most expensive averages $895.
Airlines, flight times, price calendar, and more for Boston to London
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