A Southwest Airlines jet gets ready to land at Tampa International Airport, in Tampa, Fla in June. (Skip O’Rourke/The Tampa Bay Times via AP, File)

We’re entering that sleepy period at the end of the summer. But if you still haven’t booked your dream trip there’s good news: Flying is about to get much cheaper.

Airfare tends to drop every year late in the summer and it usually stays low through the fall until people start to book their holiday trips, travel analysts say. For example, the average cost for a domestic roundtrip flight dropped to $232 in July from about $250 in June, according to the airfare tracker app Hopper. Average fares fell more in August and are projected to keep sliding to $213 in October before ticking back up for the holidays.

If you’re not tied into the school schedule and you find a getaway for September, it could be much cheaper than what you would find in July or August,” says Patrick Surry, chief data scientist for Hopper.

Demand for flights tends to fall off in the late summer months as families hunker down to prepare for the start of the school year, Surry says. Travel tends to stay slow until the holidays, so airlines often discount flights during that time period to help fill any empty seats. “You can often find some great deals,” he says.

As the chart below shows, this is pretty much the pattern every year. Flights are most expensive in early summer. Then they plunge pretty dramatically throughout the fall before picking back up at the end of the year.

Actual average domestic consumer airfare prices through July 2016 (solid line), with forecast price levels (dashed). (Courtesy of Hopper)

Before you dive into your flight search, it’s worth noting that your chances of finding a steal for your holiday trip are slim. Airlines still hike up prices for those popular travel dates, Surry says.

Plus, it may pay off to put off booking those trips. Last year, the best fares for holiday travel were typically found six weeks to a month before the holiday, says Randi Wolfson, spokeswoman for Skyscanner, a travel search engine website that compares flights, hotels and rental cars.

For instance, the greatest potential for savings on Thanksgiving flights was during the week of Halloween, according to Skyscanner. Flights booked then for travel before and after Thanksgiving were 7.7 percent less when compared to what the flight cost, on average, throughout the rest of the year.

For Christmas, flights were most affordable on the week of Thanksgiving, with airfare costing 6 percent less than it did the rest of the year. And for New Year’s Eve, the cheapest flights were booked on the week of Dec. 5.

“If you’re looking to book for the holidays our data is showing that procrastinators are winning,” Wolfson said.

Of course, there’s no promise that the patterns seen last year will play out in exactly the same way this year, Wolfson says. So the smart thing to do may be to start researching those flights now, even if you don’t actually book the trip for a while, both Surry and Wolfson say.

Airfare tends to fluctuate and people who start looking now may be able to spot a good deal if prices for holiday travel dip between now and the winter, Surry says.

Set up alerts for the dates you’re interested in so that you can get an email or text if prices drop below a certain amount, they say.

Read more:

This fee could triple the cost of your reward flight

How to know when it’s time to ditch your travel reward credit card

When does a balance transfer pay off?