WARM has a long and distinguished history in northeastern Pennsylvania broadcasting. It was the predominant Top 40 format music station in the area during the 1960s and into the 1970s. It was known during this era as "The Mighty 590". WARM has held its original call sign since it signed on the AM broadcast band in 1940. However, the station originally broadcast on a frequency of 1400 kHz during its early years. The station was an affiliate of the ABC radio network since the 1940s. After Citadel Broadcasting bought ABC Radio Networks in 2007, WARM became an ABC Radio O&O station. Citadel merged with Cumulus Media on September 16, 2011.
For a time in April 2009, WARM left the air due to transmitter problems; the station then announced that it had no plans to return. The host of the station's polka show told a reporter, "Unless there's a miracle, they ain't coming back." However, on April 23, WARM returned to the air, still airing its oldies format. On September 15, 2014 WARM went silent again, due to a transmitter failure.  The station resumed broadcasting in December 2014 and is now an affiliate of CBS Sports Radio.