Haven't gone on vacation yet? Here's the date to fly

— -- At the start of each year, I like to give a run-down on the cheapest dates to fly.

Sometimes dates move a bit depending on demand for travel and other factors, and that’s what’s happened with the cheapest day to fly at the end of summer. Peak-summer fares for U.S. travel will drop Aug. 22.

Why Aug. 22?

It’s the date most airlines use to signal the start of the cheaper fall season. The actual date varies year to year and it coincides not with the first day of autumn but with kids’ school schedules. When kids are back in class, demand for vacation travel drops and so do fares.

Is Aug. 22 a cheap day around the world?

Not necessarily. This particular date is for U.S. domestic travel. For trans-Atlantic travel, you actually get an earlier start with lower fall pricing kicking in Aug. 21.

Is every domestic route on every U.S. airline cheaper as of Aug. 22?

Not always, but on average you’ll find cheaper fares. Last week for example Southwest advertised a big sale that was good for travel starting on Aug. 22. However, Frontier also had a big sale but its deals were valid Aug. 15. There is some give-and-take on these dates so be sure to compare airfare prices on a least a few dates if you’re looking to travel in late August.

How much can you save?

These roundtrip fares were found last week for Friday/Monday flights from Chicago to Ft. Lauderdale:

Late July:
Spirit - $149
American - $247
United - $283

Late August:
United - $119
Spirit - $129
American - $193

These fares are also a great example of the need to compare (on my site or your favorite) and not simply go to the one airline site you "know" is always cheapest. No airline always has the best deal, not even that ultra-discounter.

Are there other advantages to taking a late summer vacation?

Besides the financial advantages, flying on or after Aug. 22 means avoiding long summer lines at security and bypassing crowds at airports and popular attractions. Another advantage is the weather; I like fall because of the weather, not too hot and not too cold.

Are there disadvantages?

Sure, and that’s not being able to fly with your kids (if you won’t take them out of school). Otherwise, it’s hard to see disadvantages for retired folks, young couples or solo travelers and maybe even moms and dads who would really like a nice long weekend away all to themselves.

Rick Seaney is the CEO of FareCompare, a website that curates the best deals on flights from around the world. Any opinions expressed in this column are solely those of the author.