The Foreign and Commonwealth Office has alerted travellers to wildfires burning across swathes of the western US.
California and Washington state are both identified as suffering from a number of wildfires.
“Areas of high risk are canyons, hills and forests,” the FCO said. “Monitor local media reports and follow the advice of local law enforcement officials.”
Local reports point to more than 3,000 firefighters tackling the biggest blaze north of San Francisco consuming more than 100 square miles of tinder dry land following four years of drought.
Some 20 wildfires have been reported in California, prompting evacuation orders for 13,000 people after 24 houses were burnt down on Monday.
Cooler weather yesterday helped create a buffer between the flames and 5,500 homes they could destroy, according to the BBC.
More than 300 people were moved from the path of a blaze in Washington state while another has burned more than 15,000 acres in Oregon.