What are the main causes of wildfires in Canada?

The impacts of wildfires stretch far beyond where fires start. Winds can carry smoke and hazardous particles across vast distances, often across borders, affecting air quality and the health of people and wildlife along their path. In Canada, dry spring and summer conditions, combined with higher-than-average temperatures, can increase the risk of wildland fires by drying vegetation and soils and creating conditions in which fires can spread more easily.

In 2025, 6,215 wildland fires were recorded across Canada. Of these, 532 were classified as large fires, meaning they burned more than 200 hectares. The largest fire that year burned 592,985 hectares. Between 1959 and 2025, the highest number of wildland fires was recorded in 1989, with 12,015 fires, while the lowest was recorded in 2020, with 4,014.

Natural Resources Canada uses the term “wildland fire” to describe any ignition, natural or planned, that burns in wildland areas and consumes natural fuels such as trees, brush and grass. This broader category includes forest fires, grassland fires, cultural fires and prescribed fires.

Natural Resources Canada categorizes the causes of wildland fires into three main buckets: human, nature, and unknown. Between 1970 and 2025, humans were responsible for about 54% of wildland fires with a classified cause, accounting for 205,661 fires compared with 173,420 caused by nature.

However, the number of fires does not tell the whole story. Naturally caused fires were far more destructive in terms of the area burned. Between 1970 and 2025, wildland fires burned a total of 134.1 million hectares across Canada. Fires that were caused by nature accounted for approximately 82% of that area.

While humans cause more wildland fires, naturally caused fires account for a much larger share of the land burned. One reason is that naturally caused fires, particularly those started by lightning, can occur in remote areas where they may be more difficult to detect and suppress, allowing some fires to grow much larger before firefighting resources can reach them.