(USA TODAY) -- A three-month break from airfare hikes has ended, with Southwest Airlines raising fares by $4 to $10 round-trip on most routes inside the U.S.
United Airlines led the latest price increase of $4 to $10, depending on routes, late last week. JetBlue Airways and Virgin America started raising fares Thursday. Southwest followed over the weekend.
Typically when Southwest agrees to go along with a fare hike, travelers can expect it to stick. And it didn't take long for network carriers Delta, American and US Airways to follow its lead.
The latest increase comes even as airlines have moved up fall fare sales that traditionally weren't available until the beginning of the school year. Starting Aug. 20, many airlines are planning to slash fares on their cheapest domestic seats by 10% to 20% on some routes for the fall, which traditionally is the slowest time of the year for air travel.
"Airlines only raise fares when the competition does the same and they feel consumers won't balk," said Rick Seaney, CEO of FareCompare.com. "They attempt from time to time to test both competitors and consumers. (It) appears for now they are comfortable with forward-looking bookings."
Paul Flaningan, a spokesman for Southwest, said the airline raised fares on non-sale tickets and excluded routes shorter than 500 miles.
"It continues to be a very competitive market," Flaningan said. "With costs rising and continued fuel cost fluctuation, the decision was made to match on all non-sale fares, excluding short-haul markets."
This was the seventh attempt to raise fares this year, and the fourth time that an increase has stuck.
Airlines were much more aggressive at setting prices last year, attempting to raise fares 22 times and succeeding nine times.
Airlines this year have been trying to lure travelers who are still jittery about the weak economy. Jet fuel prices have also gone down from their peaks, taking away one major justification for higher prices.
Seaney said he doesn't expect to see many more fare increases. "Given the slower fall season starting at the end of August it is unlikely we will see another hike in the next few months," he said.