Ah, the perpetual war with dynamic airfare. The price of a flight is key in determining whether or not a trip is viable, yet there's seemingly no rhyme or reason behind how much a given route will cost on a given day. As airlines collect more data and create computerized pricing algorithms, it's tougher than ever to pin down the best time to buy a plane ticket. That said, there are still a few tips that hold true for those looking to nab the best deals.
You are going to pay an awful lot to fly from Minnesota to Miami on the two days prior to Thanksgiving -- there's just no way around it. Airlines know that hordes of people attempt to travel in the run-up to Thanksgiving and Christmas, and they price seats accordingly. Instead, consider traveling on the holidays themselves. Flights on Labor Day, Independence Day, Thanksgiving Day, and even Christmas Day tend to be cheaper.
While most airlines open their booking engines a full year in advance, the best fares typically aren't found that far out. The logic works like this: an airline assumes that someone booking more than nine months out has an incredible desire to travel, and thus will pay top dollar. The same is true when booking a flight inside of two weeks -- if it's last-minute, it's probably mission critical, which means that you'll pay an arm and a leg. The sweet spot is at the two- to three-month mark. That's the period where an airline may be antsy about unsold seats, thereby softening pricing in order to ensure that it's near capacity on flight day.
Businesspeople and consultants typically travel on Sunday evenings, Monday mornings, and Friday mornings. You'll do yourself a solid if you look for flights on Tuesday, Wednesday and Saturday, as those are generally less busy days for business travel.
A great example of this working out is JetBlue's $99 introductory fares to Cuba. Whenever an airline launches a new route, it typically sells fares at a steep discount as a marketing tactic. The airline needs to drum up interest in a new route and grab the attention of frequent business travelers who may be flying that route with a competitor airline. Southwest in particular has been good about launching new routes with super cheap fares, so keep an eye out for new routes opening up at airports near you.