W.J. De Groot and M.E. Alexander first introduced the concept of displaying head fire intensities with the use of the Canadian Forest Fire Danger Rating System in 1986. The idea has now been extended to flank and back fire intensites. This paper will describe the extent to which various fire management agencies in Canada have applied the diurnal fire intensity concept in daily operational use for safe and productive wildland firefighting since that time, most notably by the British Columbia Forest Service.