$219 - Flights to San Francisco on JetBlue

JetBlue and Virgin are two of the best airlines to fly around the US right now. JetBlue is now offering the cheapest flights to San Francisco from Boston for $219 including all taxes and fees.

Must fly on Saturdays and Tuesdays.

If you fly other days of the week, you can easily keep your costs below $300, and on most days, under $250 as well.

Virgin also offers flights to San Francisco, as well as to LA and San Diego, if you’re looking for a little California adventure.