CKSY signed on the air on July 1, 1986. It originally broadcast on 95.1 FM, which had previously been the frequency used by CBEE-FM, a rebroadcaster of CBC Radio One station CBE in Windsor, now at 88.1 FM. CKSY aired easy listening music branded as Cosy, which evolved into a soft adult contemporary format by the mid-1990s.
On May 4, 2002, CKSY switched frequencies with sister stationCKUE, relocating to its current frequency of 94.3 FM. In 2005, CKSY and CKUE were acquired by Blackburn Radio.
By 2010, the station had dropped much of its older-skewing and softer titles from its playlist. It adopted a brighter, more contemporary music mix, while remaining within the boundaries of the AC format. In 2014, sister station CKUE-FM discontinued its active rock sound for a soft AC format.[2] It later shifted to a classic rock format as Cool FM.
