August is the cheapest month to fly this route, with average fares around $398 round trip.
Average round-trip fares by departure month, based on current availability.
| Month | Avg Price | Lowest | Relative Cost | |
|---|---|---|---|---|
| May 2026 | $448 | $388 | Peak | |
| June 2026 | $431 | $402 | ||
| July 2026 | $407 | $368 | ||
| August 2026 | $398 | $368 | Best |
Departing on Wednesday offers the lowest average fares at $396. Sunday departures are the most expensive at $443, 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 Cancun is August, with average round-trip fares around $398. The lowest fare found in August is $368.
Wednesday departures are the cheapest, averaging $396 round trip. The most expensive day is Sunday at $443.
Based on current pricing trends, booking for August travel offers the best value. Avoid May if possible, as fares average $448 compared to $398 in the cheapest month. June is a solid middle-ground option at $431.
Flying in August instead of May can save you approximately $50 per round trip. The cheapest month averages $398 while the most expensive averages $448.
Airlines, flight times, price calendar, and more for Seattle to Cancun
View SEA → CUN Details