The Southwest Airlines Low-Fare Calendar is one of my favorite tools for planning trips in advance. I like how it gives a full view of the month, so I can decide not only where I want to go but also the best time to book. For example, I planned a summer trip to Florida months in advance and managed to snag a fare that was almost $100 cheaper than what I saw later. Visit: https://airlinesofficelocation.com/blog/southwest-airlines-low-fare-calendar/