Cheap flights from Seattle to Boston from R3 375

In general, May is the cheapest month to fly from Seattle to Boston. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around R6 306. If you aren’t able to travel during the month of May, then book flights to Boston from Seattle during February instead. Flights to Boston in February, while not as cheap as those in May, still average around R6 371.

You are more likely to see cheaper flights to Boston from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Boston for around R7 317 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Boston from Seattle for as low as R6 273 on momondo.

Historically, on average around 17% of flights between Seattle and Boston have experienced a delay on any given week. The average delay length over the past 12 months has been 176 minutes.

Generally, flights departing at night tend to experience fewer delays. Flights departing in the early afternoon have, in the past, seen delays more frequently in comparison.

Saturday is statistically the day of the week that experiences the fewest delays on this flight route. Monday has historically seen more delays on average compared to the rest of the week.

According to our data, Delta have had the fewest delays on this route over the last 12 months, with about 13% of their flights experiencing any sort of delay.

18 flights are operational daily from Seattle to Boston as of October 2026. The most popular departure time for this route is 23:00, with 41% of flights per day taking off in the evening.

As of October 2026, 126 flights take off from Seattle and land in Boston each week. The most common flight departure day for this route is Thu, with 24% of weekly flights taking off on this day.