A Study of the Relation of Meteorological Variables to Monthly Provincial Area Burned by Wildfire in Canada (1953–80)

The relation between meteorological variables and the monthly area burned by wildfire from May to August 1953–80 in nine Canadian "provinces" was investigated. A purely statistical approach to estimating the monthly provincial area burned, using meteorological variables as predictors, succeeded in explaining 30% of the variance west of Lake Nipigon and about 11% east of Lake Nipigon. Long sequences of days with less than 1.5 mm of rain or days with relative humidities less than 60% proved to have the highest correlation with area burned. These long sequences were assumed to be associated with blocking highs in the westerlies. Bad fire months were independent of rainfall amount but significantly dependent on rainfall frequency, temperature, and relative humidity.