August is the cheapest month to fly this route, with average fares around $206 round trip.
Average round-trip fares by departure month, based on current availability.
| Month | Avg Price | Lowest | Relative Cost | |
|---|---|---|---|---|
| May 2026 | $263 | $189 | Peak | |
| June 2026 | $217 | $189 | ||
| July 2026 | $220 | $185 | ||
| August 2026 | $206 | $185 | Best |
Departing on Wednesday offers the lowest average fares at $196. Sunday departures are the most expensive at $242, a difference of $46.
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 Diego to Seattle is August, with average round-trip fares around $206. The lowest fare found in August is $185.
Wednesday departures are the cheapest, averaging $196 round trip. The most expensive day is Sunday at $242.
Based on current pricing trends, booking for August travel offers the best value. Avoid May if possible, as fares average $263 compared to $206 in the cheapest month. July is a solid middle-ground option at $220.
Flying in August instead of May can save you approximately $57 per round trip. The cheapest month averages $206 while the most expensive averages $263.
Airlines, flight times, price calendar, and more for San Diego to Seattle
View SAN → SEA Details