Southwest is offering 40% off their flights November 28th – December 12th & January 7th – February 14th when you use Southwest promo code BIGDEAL40 on their website through October 11th. Roundtrip is required. Flights to Chicago (brrrrr….) from LaGuardia are only $46 each way, for example.
Majors appear to be matching in some markets and not requiring a code or roundtrip in many cases. Worth a look during that slow period.