I used to think waiting until the last minute was the best way to snag a deal, but Southwest proved me wrong during a trip to Nashville. I held off booking, hoping for a price drop, only to watch my $140 ticket jump to $350 three days before the flight!
Generally, Southwest flights don't get cheaper closer to the date; they actually tend to spike once you're within that 14-day window. The sweet spot is usually booking 1-3 months out. However, here’s the real "hack": because they have no change fees, I now book as early as possible. If I check back and see the price has actually dropped, I just "modify" my flight to the cheaper fare and pocket the difference as a travel credit.