August is the cheapest month to fly this route, with average fares around $197 round trip.
Average round-trip fares by departure month, based on current availability.
| Month | Avg Price | Lowest | Relative Cost | |
|---|---|---|---|---|
| May 2026 | $241 | $199 | Peak | |
| June 2026 | $206 | $177 | ||
| July 2026 | $204 | $177 | ||
| August 2026 | $197 | $177 | Best |
Departing on Tuesday offers the lowest average fares at $182. Saturday departures are the most expensive at $233, a difference of $51.
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 Seattle is August, with average round-trip fares around $197. The lowest fare found in August is $177.
Tuesday departures are the cheapest, averaging $182 round trip. The most expensive day is Saturday at $233.
Based on current pricing trends, booking for August travel offers the best value. Avoid May if possible, as fares average $241 compared to $197 in the cheapest month. June is a solid middle-ground option at $206.
Flying in August instead of May can save you approximately $44 per round trip. The cheapest month averages $197 while the most expensive averages $241.
Airlines, flight times, price calendar, and more for San Francisco to Seattle
View SFO → SEA Details