In the US state of Oregon, the nation’s largest active wildfire has burned through more than 300,000 acres, prompting thousands of evacuations.
The Bootleg Fire, already among the biggest in the state’s recent history, is one of more than 80 major blazes raging across 11 western states.
Fed by hot temperatures and intense winds, the Bootleg has been burning since 6 July.
In neighbouring Canada, heat waves have also fuelled hundreds of fires.
Wildfires have torn through more than 1.1m acres in the US – mainly in western states – according to the National Interagency Fire Center.
Climate change increases the risk of the hot, dry weather that is likely to fuel wildfires.
The world has already warmed by about 1.2C since the industrial era began and temperatures will keep rising unless governments around the world make steep cuts to emissions.