The station signed on the air on February 4, 1960 as KBAY-FM. It was owned by Kaiser Broadcasting, a company started by local industrialist Henry J. Kaiser. It aired a "good music" format, mostly instrumental easy listening with some middle of the road songs and soft pop vocals. In 1964, the call sign switched to KFOG in honor of the city's fog layer, and the station aired a beautiful music format, again largely instrumental music, cover versions of popular songs with some Broadway and Hollywoodshow tunes. Within a few years, KFOG got competition from other beautiful music stations: KABL-AM-FM and from KOIT, as well as San Jose-based KBAY. For the next two decades, beautiful music was popular in the Bay Area. By the early 1980s, the format was showing signs of aging. KFOG was acquired by General Electric in 1974.
Switch to Timeless Rock
On September 16, 1982, KFOG dropped the easy listening format for a blend of album-oriented rock and classic rock, which the station called "Timeless Rock." The first song on the new format was "Rock This Town" by The Stray Cats. The station featured a wide range of music, from the psychedelic sounds of the Grateful Dead and Jefferson Airplane to newer artists such as Prince, the Eurythmics, and the Thompson Twins. KFOG avoided commercial-sounding bands such as Loverboy and REO Speedwagon, which were widely played on more mass-appeal AOR stations at the time. KFOG was inspired by San Francisco's freeform rock radio heritage, dating back to KSAN, a pioneering progressive rock station. When KFOG changed to rock in the early 1980s, the Bay Area already had numerous competing rock stations; KMEL was the established, tightly-formatted AOR station that had been playing rock music since 1977. KRQR was the hard rock station and KQAK was a new station with a friendly, loosely programmed, personality-driven alternative rock/new wave format. There were two other rock stations in the South Bay - KSJO and KOME. One other San Francisco rock station, KSFX, switched to talk radio in May of that year. Of the six Bay Area rock stations that were on the air in late 1982, KFOG had been the last of the heritage rock stations. In 1989, KFOG was acquired by the Susquehanna Radio Corp., along with KNBR, for $17.5 million. Susquehanna later merged into Cumulus Media, the current owner.
AAA and alternative rock
The station evolved over the years, but KFOG aired an eclectic rock format for more than a quarter century. In the 1990s, it adjusted its playlist to an adult album alternative direction. In August 1995, it became "KFOG 97.7 and 104.5," when Susquehanna acquired San Jose station KHQT and turned it into KFFG, simulcasting KFOG on a full-time basis. On March 31, 2016, KFOG took all of its DJs off the air and began promoting an "evolution" to take place on April 20. On that day, at 6 a.m., KFOG relaunched its AAA format under the new slogan "Music Matters," and shifted its playlist to focus on songs from the 1990s to the present day. The first song under the "Music Matters" branding was "Times Like These" by Foo Fighters. As part of the change, former New York City rock DJ Bryan Schock was hired as Operations Manager/Program Director for KFOG and classic rock sister station KSAN. Most of the KFOG airstaff, including morning host Renee Richardson, midday host Annalisa, afternoon host Bill Webster, night host Dred Scott, and weekend host Rosalie Howarth, were let go from the station. By 2018, the station gradually transitioned to a more mainstream alternative format. It then directly competed with KITS. At 9:00 p.m. on May 31, 2019, KFOG slightly re-branded as "KFOG 104.5," as KFFG was sold off to EMF and became K-Love affiliate KJLV; the station adopted a new logo to reflect the sale of the repeater. The last song before the simulcast broke was "High Hopes" by Panic! At The Disco.
Switch to KNBR-FM
On August 26, 2019, Cumulus announced that KFOG would drop its rock format on September 6th to simulcast sister station KNBR. On its final day as a music station, starting at 6 a.m., KFOG aired a tribute to its long run as a rock station with a day-long marathon of old "10@10" broadcasts and recordings taken from the station's "Live From the Archives" CD series. The exception was the 8 a.m. hour, a repeat of Dave Morey's final morning show before his retirement in 2008, and the 5 p.m. hour, in which KFOG paid tribute to longtime DJ Mike ‘M Dung’ Slavko's Sunday night freeform radio program "The Idiot Show". In addition, the station identifications for that day were taken from the pre-1982 beautiful music format. During the final hour, KFOG rebroadcast its 1982 flip to AAA, followed by a "10@10" broadcast of "666 - Day of Doom Devil Music" which originally aired June 6, 2006, then a short set of songs which culminated with "Brokedown Palace" by the Grateful Dead. After a final sign-off consisting of eight minutes of waves, seagulls, and foghorns that were the station's longtime trademark, and a minute of silence, KFOG officially flipped to the simulcast. On the same day, the call signKNBR-FM was adopted; the KFOG call letters have since been warehoused on an AM station in Little Rock, Arkansas, the former KPZK.
Booster
The station is rebroadcast on the following FM booster:
HD radio
As KFOG, it broadcast two feeds in HD Radio, the first was a simulcast of the analog feed and the second carried "All-10@10-All-The-Time." The HD2 feed was taken off air in 2015. The HD1 feed returned when the station became KNBR-FM.
