Question

What percent of Ontario's forest fires are caused by lightning?

Answer 1

45%

Explanation:

Forest fires started by lightning:

Represent 45 per cent of all fires;
Represent 81 per cent of the total area burned; and
Occur in remote locations and often in multiple clusters.
Forest fire occurrence, and area burned are highly variable:

The area burned by forest fires ranges from 0.7 million to 7.6 million hectares/year;
The average area burned is 2.3 million hectares/year;
The average fire occurrence is 8000 fires a year ; and
The average fire suppression costs are $500 million to $1 billion annually.

Reference:
Forest Fires and Lightning (2017): https://www.canada.ca/en/environment-climate-change/services/lightning/forest-fires.html