There’s finally some good news for travelers in a hot, crowded, expensive summer: Airfare is starting to cool. The bad news? It isn’t expected to last.

Domestic round-trip airfare — already a big bargain compared with unusually pricey international flights over the summer — dropped to an average of $257 in the last week of July, according to new data from the flight-booking app Hopper. That’s down 11 percent from last year and 2019, and a decrease of more than 14 percent from the roughly $300 people were paying for round-trip flights over the Fourth of July weekend.

Even international airfare is falling, Hopper’s data shows. A good deal for a round-trip flight to Europe is averaging $813, down a bit from last year but still 7 percent higher than before the pandemic. That’s still significantly cheaper than earlier in the summer; airfare to Europe was averaging $1,371 over the Fourth of July holiday.

Budget-conscious travelers should take advantage while they can: As the holidays approach, many of the deals will disappear.

Typical seasonality is a big factor, said Katy Nastro, a travel expert at the cheap-flight alert service Going.

“Airfare in the middle of July is going to be quite more expensive versus traveling in September and October, regardless if you’re traveling internationally or domestically,” she said. “That’s because kids are back in school. Summer might be the only time people can take an extended vacation.”

But there are more forces at work. The cost of flights in the United States skyrocketed last summer, when travel to many international destinations was still complicated or impossible because of the pandemic.

“After people took that first domestic trip, a lot of them overpaid and were like: ‘Whoa, sticker shock. I might be more price-conscious looking forward,’” Nastro said.

Fares for domestic flights have been falling considerably as airlines added capacity to U.S. routes, jet fuel prices dropped, competition increased and travelers shifted to more global getaways.

In recent earnings reports, some airlines noted that their business at home was suffering because of Americans’ appetites to get away. JetBlue, for example, said in its report that a “greater than expected shift of pent-up COVID demand to long-haul international markets” was putting pressure on demand for domestic trips this summer.

“People have been willing to pay incredibly high prices” for their trips abroad, said Hayley Berg, Hopper’s lead economist. “There’s obviously an intense demand for international travel that we saw this summer.”