Fire Behavior Normals

Rate of Spread

Rate of Spread (ROS) is the predicted speed of the fire at the front or head of the fire (where the fire moves fastest), and takes into account both crowning and spotting. It is measured in metres per minute and is based on the Fuel Type, Initial Spread Index, Buildup Index, and several fuel-specific parameters such as phenological state (leafless or green) in deciduous trees, crown base height in coniferous trees, and percent curing in grasses.

More information about the Canadian Forest Fire Weather Index (FWI) System is available in the Background Information.

Fire Behavior Normals represent the average value of a fire behavior element over the 30-year period from 1981 to 2010.