Summer travel isn't as easy as it used to be for airlines

July is the busiest month of travel in the U.S.Spencer Platt | Getty Images News | Getty ImagesMaking money in the summer is not as easy as it used to be for airlines.Airlines have drawn down their schedules in August for a variety of reasons

Some travelers are opting to fly earlier, in June or even May, as schools let out sooner than they used to

Demand for flights to Europe has also been moving from the sweltering, crowded summer to the fall, airline executives have said, especially for travelers with more flexibility, retirees.Carriers still make the bulk of their money in the second and third quarters

But as travel demand has shifted, and in some cases customers have become altogether unpredictable, making the third quarter less of a shoo-in moneymaker for airlines.Change of plans, pricier ticketsAirline planners have been forced to get more surgical with schedules in August as leisure demand tapers off from the late spring and summer peaks

Labor and other costs have jumped after the pandemic, so getting the mix of flights right is essential.Carriers across the industry have been taking flights off the schedule after an overhang of too much capacity pushed down fares this summer

But the capacity cuts are set to further drive up airfares, which rose 0.7% in July from last year, and a seasonally adjusted 4% jump from June to July, according to the U.S. inflation read.U.S. airlines' domestic capacity is down 6% in August from July, according to aviation data firm Cirium

The same period last year, they cut domestic capacity just over 4% compared with just a 0.6% downsize between the months in 2023, Cirium said

To attract more customers, many airlines slashed prices, even for flights in the summer peaks in late June and July.Demand has imved, airline executives said on earnings calls in recent months, but carriers including Delta, American, United and Southwest last month lowered their 2025 fit forecasts compared with their sunnier outlooks at the start of the year.Further complicating matters, some travelers have been also waiting until the last minute to book flights."It really was, I would say, middle of May, when we started seeing Memorial Day bookings pick up," JetBlue Airways President Marty St

George told investors last month. "We had a fantastic Memorial Day, much better than forecast, and that really carried into June

But it does have the feeling of people just waited a long time to make the final decisions." Read more CNBC airline newsSpirit Airlines warns it might not be able to survive a year without more cashWhy Delta and United are pulling away from the airline packHow much are Southwest's new assigned seats? It depends'He's showing up.' Things are getting better at Boeing under CEO Ortberg

Can he keep it going?There's always next yearNow, some airlines are already thinking how to tackle ever-changing travel patterns next year."Schools are going back earlier and earlier but what you also see is schools are getting out earlier and earlier," Brian Znotins, American Airlines' vice president of network planning and schedule, told CNBC.Public schools in Dallas and Fort Worth, Texas, returned on Aug. 5, and Atlanta public schools resumed Aug. 4

In 2023, more than half of the country's public school students went back to classrooms by mid-August, according to the Pew Re Center.Southwest, with its Texas roots, its summer schedule on Aug. 5 this year, compared with Aug. 15 in 2023

American, for its part, is shifting some peak flying next year."We're moving our whole summer schedule change to the week before Memorial Day," Znotins said. "That's response to schools letting out in the spring." Those plans include additions of a host of long-haul international flights."We are a year-round airline," he continued

Znotins said the carrier has to not just make sure there are enough seats for peak periods, but know when to cut back in lighter quarters, the first three months of the year."For a network planner, the harder schedules to build are the ones where there's lower demand because you can't just count on demand coming to your flights," Znotins said. "When demand is lower, you need to find ways to attract customers to your flights with a good quality schedule and duct changes."American said its schedule by seats in August was on par with July in 2019, but that this year it was 6% lower in August from July.American forecast last month it could lose an adjusted 10 cents to 60 cents a in the third quarter, below what analysts are expecting

CEO Robert Isom said on an earnings call that "July has been tough," though the carrier says trends have imved.The capacity cuts, coupled with more encouraging booking patterns lately, are fueling optimism a better supply and demand balance in the coming weeks."The mistake some airlines make, you tend to try to build a church for Easter Sunday: You build your capacity foundation for those peak periods and then you have way too many [employees]," said Raymond James airline analyst Savanthi Syth.She said it was unusual to see airlines across the board pruning their summer schedules before even the peak period , but she is upbeat demand, and fares, going forward."Time has passed and people are getting a little more certainty on what their future looks and they're more willing to spend," she said.Don’t miss these insights from CNBC Forget Palantir