If you're planning a fall getaway, this could be your lucky day. For the next 48 hours, Southwest is having a mega sale on post-summer airfares on all its routes. Sale prices range from $30 to $90 for one-way flights, depending on the distance flown. The fine print: Travel dates are from September 9 to November 18, for flights any day of the week except Friday and Sunday. Hurry—the sale ends tomorrow, July 8, at 11:59PST (July 9, 2:59AM EST).