Just in time for Memorial Day, airlines significantly raised fares in an effort to offset the soaring cost of fuel.

United, American and Delta ratcheted up roundtrip ticket prices by up to $60. Budget carrier AirTran has raised its coach fares by $30.

The increases came just days after American announced it would begin charging customers $15 to check a single bag. Many other carriers that already charge $25 for a second checked bag said they're considering following American's move.

Airlines have come under intense pressure to boost revenue and cut costs because the added fuel burden. The price of jet fuel has gone up more than 40 percent since the start of the year.