August is the cheapest month to fly this route, with average fares around $203 round trip.
Average round-trip fares by departure month, based on current availability.
| Month | Avg Price | Lowest | Relative Cost | |
|---|---|---|---|---|
| May 2026 | $222 | $199 | Peak | |
| June 2026 | $209 | $177 | ||
| July 2026 | $205 | $177 | ||
| August 2026 | $203 | $177 | Best |
Departing on Wednesday offers the lowest average fares at $182. Sunday departures are the most expensive at $229, a difference of $47.
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 Seattle to San Francisco is August, with average round-trip fares around $203. The lowest fare found in August is $177.
Wednesday departures are the cheapest, averaging $182 round trip. The most expensive day is Sunday at $229.
Based on current pricing trends, booking for August travel offers the best value. Avoid May if possible, as fares average $222 compared to $203 in the cheapest month. June is a solid middle-ground option at $209.
Flying in August instead of May can save you approximately $19 per round trip. The cheapest month averages $203 while the most expensive averages $222.
Airlines, flight times, price calendar, and more for Seattle to San Francisco
View SEA → SFO Details