Some Major US Airlines Hike Fares By $3 One-Way

Delta was the first airline to hike fares.

— -- Some major U.S. commercial airlines said they plan to raise passenger fares by $3 per one-way flight.

The fare increase for Delta and Southwest went into effect Monday, while the increase for JetBlue went into effect today. It was not clear when the increases for the other airlines will take effect.

The fare hike will affect all short, medium and long-haul flights, which range from 300 to 2,700 miles one way, according to FareCompare.com.

"Southwest Airlines implemented a modest increase of $3 each way Monday night in markets across our system. Southwest Airlines is the nation’s low fare leader and has been for nearly 45 years," the statement said. "In addition to our everyday low fares, we don’t nickel-and-dime our customers with hidden fees: we never charge change fees, and Southwest is the only domestic airline that allows every customer to check two bags free of charge (weight and size limitations apply)."

ABC News' Becky Perlow and Erin Dooley contributed to this report.