Officials say a wildfire in Northern California grew dramatically overnight and is largely burning out of control.
CAL FIRE says the County Fire northwest of Sacramento scorched at least 44,500 acres by Monday morning. It is just three percent contained.
The fire, burning in Yolo, Napa and Lake counties is threatening 100 buildings and has forced evacuations.
CAL FIRE says strong winds, high temperatures and low humidity are fueling the blaze.
Smoke and ash are contributing to poor air quality in the San Francisco Bay Area and California wine country.
Hot, dry conditions are fueling blazes in several Western states. Firefighters in California are battling at least 11 major incidents.
Forecasters say the threat of wildfires will diminish in the U.S. Southwest this month but increase in the Northwest and along much of the California coast.
The National Interagency Fire Center said Sunday that the summer monsoon should bring enough rain to Arizona, Colorado and New Mexico in early July to reduce the risk of major fires. But the danger remains high through the end of July in Utah and parts of California, Idaho, Nevada, Oregon and Washington.
By August, the threat spreads across much of the Northwest, extending east into most of Montana. The danger in the Northwest is expected to persist through September.
The fire center updates the outlook every month from its headquarters in Boise, Idaho.