To take advantage of the low prices, you have to buy before midnight on July 20 and travel between August 14 and November 14. Cities with $29 tickets include Atlanta, Austin, Denver, Las Vegas, Miami, Milwaukee, Nashville, New Orleans, Orlando, Philadelphia, and Tampa, among others.
Plot out all the details of flying Frontier before you pull the trigger, though. It's a budget airline, and that means you could see additional costs for luggage and seat selection. But pack like a champ and find an unexpected destination for a well-deserved weekend away.