According to the trend of travelers using the airline's services, Tuesday, Wednesday, and Saturday are the cheapest days to fly Southwest Airlines. Even though the airline is a low-cost carrier with flights to over 100 locations, experienced travelers nevertheless utilize various tactics to save even more money.

For Southwest Airlines in 2026, the cheapest days to fly consistently remain Tuesday and Wednesday. These mid-week days see the lowest demand from both business travelers and weekend vacationers, leading the airline to load its most aggressive "Wanna Get Away" and "Basic" fare deals during these windows. Conversely, Friday and Sunday are the most expensive days to fly due to the high volume of travelers heading out for or returning from weekend trips. To find the absolute lowest fares, Southwest's Low Fare Calendar is the best tool, as it allows you to see a full month of pricing at once. You will often find one-way deals for as low as $49 to $69 on these mid-week dates, especially if you book at least 21 days in advance. Additionally, flights that depart very early in the morning (before 7:00 AM) or late at night often carry lower price tags than mid-day departures. Because Southwest does not charge for the first two checked bags, these mid-week deals represent some of the best total travel values in the domestic U.S. market.