Spirit's new deal is available for booking through Wednesday at 11:59 p.m. ET. Destinations include Ft. Lauderdale, Las Vegas, and Nassau.
Flights to Berlin, Dusseldorf, Frankfurt, and Munich are featured in LTU's new offer. Travel is valid through late March.
Lufthansa's new deal includes flights to London, Munich, Casablanca, and Muscat. Book tickets by Thursday.
United's Brussels deal includes departures from Boston, Minneapolis, Las Vegas, and San Francisco. Book tickets by Thursday.
Southwest's latest sale features November flights to cities such as Chicago, Austin, San Diego, and Washington, D.C.
