Cheap flights from Seattle to Boston from $119

In general, September 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 $307. If you aren’t able to travel during the month of September, then book flights to Boston from Seattle during October instead. Flights to Boston in October, while not as cheap as those in September, still average around $307.

The cheapest day to depart from Seattle to Boston is on a Tuesday when prices can be found for as low as $356. Be sure to avoid booking your departure on a Monday as prices are generally higher than usual. According to our data, the average ticket price to Boston on Monday is $441.

According to our data, the cheapest time of day to fly to Boston is at noon. momondo users have found flights departing from Seattle to Boston at noon for as low as $232. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. In the morning is when there is more demand to fly to Boston, so prices are often more expensive at around $430 per ticket.

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 $382 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 $329 on momondo.

There are 4 cabin classes 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.

United Airlines, Southwest, and Frontier are the most popular carriers operating from Seattle/Tacoma Intl to Boston Logan Intl

Delta, Alaska Airlines and JetBlue are the top three most popular airlines that fly to Boston from Seattle according to our data. Delta is the first choice among our users, with 39% of people opting to fly with this airline when traveling to Boston. Keep in mind that there are 8 different airlines that fly to Boston on a routine basis, so you have a few additional options to choose from.

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 168 minutes.

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

Tuesday is statistically the day of the week which experiences the fewest number of 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 have had the least number of delays on this route over the last 12 months; with about 10% of their flights experiencing any sort of delay.

4 flights are operational daily from Seattle to Boston as of March 2026. The most popular departure time for this route is 10:00PM, with 43% of flights per day taking off at noon.

As of March 2026, 29 flights take off from Seattle and land in Boston each week. The most common flight departure day for this route is Sat, with 69% of weekly flights taking off on this day.