Cheap flights from Seattle to Boston from C$ 170

The cheapest month to fly to Boston from Seattle is in September. Flight prices, which tend to average around C$ 421, are often lower during this time because this is during the off-season. If you are unable to visit Boston during the month of September, then departing from Seattle during the month October is also very affordable. Most momondo users find prices during this month for around C$ 421.

On average, the least expensive day to fly to Boston from Seattle is on a Thursday. momondo users have found tickets for Thursday departures for as low as C$ 421. However, this price may fluctuate depending on the airline, the season, and holidays. Flights from Seattle to Boston on a Tuesday will generally be more expensive and average around C$ 1,151. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

Flying to Boston from Seattle in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as C$ 407 when looking at flights departing in the afternoon. Flights in the morning are often more expensive with an average ticket price of C$ 758.

Fly from Seattle/Tacoma Intl to Boston Logan Intl for the best Seattle/Tacoma Intl - Boston Logan Intl flight prices

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 C$ 524 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Boston from Seattle for as low as C$ 451 on momondo.

There is only 1 cabin class available to choose from on Seattle/Tacoma Intl to Boston Logan Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

No. A direct flight is the cheapest option for a flight between Seattle to Boston.

As of March 2026, prices for Seattle to Boston flights are approximately 0% more expensive when compared to flights at the same time last year.

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 169 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.

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

According to our data, Delta has had the least delays on this route over the last 12 months, with about 10% of their flights experiencing any sort of delay.

As of March 2026, there are 17 flights per day flying from Seattle to Boston. The most common time of day flights depart is 3:00p.m., with 51% of flights taking off in the afternoon.

The number of flights available between Seattle and Boston is 121 per week as of March 2026. The most frequent departure day is Fri, with 19% of weekly flights leaving on this day.