Firefighters in the Pacific Northwest have received a helping hand from cooler, damp weather in their battle against an array of deadly wildfires, even as unco-operative winds in southern California spread another landscape-scorching blaze.
The weather shift, which followed intermittently heavy showers on Friday, helped more than 9000 personnel fight 29 wildfires across Washington and Oregon, including the Riverside Fire southeast of Portland, the US Forestry Service said.
But even after the rainfall west of the Cascade Mountains, the fire was still feeding on deep layers of long-dead vegetation that is abundant in the western wilderness.
"Rain doesn't do much to put out the fire unless we get a lot of it," Incident Commander Alan Sinclair said on Saturday. "But the good news is the cool, damp weather is moderating fire activity and giving us a chance to make progress in containment efforts."
The Riverside Fire has burned nearly 55,847 hectares and is only 11 per cent contained,
The unusually ferocious wildfires have claimed at least eight lives in Oregon and one in Washington state, blackening 650,000 hectares in the two states since September 7 and incinerating several small towns.
Thousands of evacuees, particularly in Oregon, have been forced into emergency accommodation.
To the south, flames have charred a record 1.3 million hectares in California, killing 26 people and destroying more than 5800 structures since mid-August, the state Department of Forestry and Fire Protection (Cal Fire) said.
A force of more than 19,000 firefighters made headway against the 27 major blazes they had been battling since August as searing temperatures diminished somewhat, it said.
But at least one blaze, the Bobcat Fire in the San Gabriel Mountains northeast of Los Angeles, spread rapidly in high winds, leaving more than 36,826 hectares scorched.
Winds remained a threat, with forecasts calling for gusts 40km/h amid very low humidity, Cal Fire said.
Australian Associated Press