KXSN (98.1 FM) is a commercial radio station in San Diego, California, branded Sunny 98.1. Owned by Audacy, Inc., the station airs a classic hits radio format. The station's studios and offices are located in San Diego's Stonecrest area, off Granite Ridge Drive, and its transmitter is off La Jolla Scenic Drive South in La Jolla.

The station first signed on the air on February 4, 1960, as KJLM. It was owned by E. Edward Jacobson and it operated at only 4,500 watts, a fraction of its current power. The station aired what it described as a "good music" format, a mix of middle of the road (MOR) and easy listening music.

In 1968, Jacobson changed the station's call sign to KDIG but remained as owner and president, and continued the MOR format.

The station changed hands in 1971, getting sold to West Coast Media.

In 1974, the call letters were switched to KIFM and the format moved to what West Coast described as "mellow music", a mix of soft rock and soft adult contemporary. In the 1980s, KIFM experimented with a contemporary jazz program at night, called "Lights Out San Diego".

In September 1987, as Lights Out San Diego gained in popularity, KIFM went with smooth jazz around the clock as "Smooth Jazz 98.1".

In 1996, KIFM was bought by Jefferson-Pilot Broadcasting for $28.75 million. In April 2006, Jefferson-Pilot would be acquired by Lincoln Financial Group. The media division became Lincoln Financial Media.

During smooth jazz's popularity, KIFM was one of the top rated stations in San Diego and was the 2005 winner of the Marconi Award.