Much of the rain will drop over the west slopes of the Cascade Mountains, exactly where Oregon Department of Forestry fire chief Doug Grafe would "ask for it," he says.
The state has seen more than 3.4 million acres scorched so far this year, killing 25 people and reducing hundreds of homes to embers.
It's one of about 59 uncontained large fires burning across the US West, according the National Interagency Fire Center.
Many still leaving their homes behind
"I hope my neighbors all get out and they're all safe," he said. "And I just pray we come back to a home and if we don't, it's just stuff, right?"
Similar scenes have played out across the state in past weeks, as violent flames forced residents out of their homes.
California Gov. Gavin Newsom says climate change is to blame.
"The fundamental facts cannot be denied," the governor said. "The trendlines are not going in the right direction."
Since the beginning of the year, California has seen nearly 7,900 wildfires, CAL Fire says. More than 6,200 structures across the state have been damaged or destroyed.
New danger looms
In Oregon, Sen. Jeff Merkley says surveying the damage looked like a "World War II ground hit by fire bombing and thousands of homes destroyed, residences destroyed."
"A lot of them are apartment buildings and mobile home parks, manufactured housing parks, so a lot of the families who had very modest housing, the most affordable housing, the housing is gone. We had commercial districts burnt to the ground. It's overwhelming."
The ground that's been destroyed can give way to another danger now looming: mudslides.
Mudslides can occur when burned ground that's missing the vegetation which stabilizes the soil grows heavy with rainwater and, unable to hold its weight, begin flowing down a slope, gathering debris and speed as it goes.