Cheap flights from Boston to Seattle from R3 279

The cheapest month to fly to Seattle from Boston is in March. Flight prices, which tend to average around R5 916, are often lower during this time because this is during the off-season. If you aren’t able to travel to Seattle during the month of March, then flying in May is also cheap. Prices for this month can be found on momondo for an average of R6 279.

You are more likely to see cheaper flights to Seattle from Boston when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around R7 239 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from Boston for as low as R6 444 on momondo.

Historically, on average around 18% of flights between Boston and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 159 minutes.

Generally, flights departing in the morning tend to experience fewer delays. Flights departing in the evening have, in the past, seen delays more frequently in comparison.

Wednesday 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 have had the fewest delays on this route over the last 12 months, with about 16% of their flights experiencing any sort of delay.

As of November 2026, there are 15 flights per day flying from Boston to Seattle. The most common time of day flights depart is 7:00, with 55% of flights taking off at midday.

111 flights are operational weekly from Boston to Seattle as of November 2026. The most popular departure day for this route is Tue, with 23% of flights per week taking off on this day.