But rain also carries the risk of flash flooding in areas that have burned, according to the National Weather Service. Areas near the Archie Creek and Thielsen fires are flash flood watches until 11 p.m. PT Thursday.
“Locally heavy rain is possible late this afternoon through this evening across the Cascades and Cascade foothills,” forecasters said.
Glide and a stretch of Highway 138 near the Archie Creek Fire near Diamond Lake also could be vulnerable to debris washed down from steep, burned-out areas, according to the weather service.
But the rain also could help improve horrendous air quality caused by smoke from the fires raging across the West Coast, Oregon Public Broadcasting reported.
Rainfall will change the atmosphere, pushing smoke-free air from above 3,500 feet downward to dilute the smoke, NWS meteorologist David Bishop told the outlet.
Authorities also warned drivers that as little as a foot of floodwaters can sweep a car away.
More than 30 people have died across Oregon, Washington and California in the wildfires in recent weeks -- 25 in the Golden State alone, according to authorities. Some of them were found trapped in vehicles or near roads, killed while apparently trying to escape.
In California, which is still experiencing a drought, authorities said there were at least 26 major wildfires burning Thursday, with more than 17,000 firefighters battling them and more than 100 aircraft involved in the effort.
Hundreds of Marines and Navy sailors were set to begin firefighter training this week to help take on the record-setting wildfire season. They will join Army soldiers already helping out in the state.
Fox News' Christina Coleman contributed to this report.