The rapidly moving Atlas Peak fire was visible throughout Napa Valley and heavy smoke was draping over the region.
Several fast-moving wildfires have ravaged Northern California's wine country, destroying properties and crops, triggering widespread evacuations and prompting California's governor to declare a state of emergency.
Officials were working to manage more than a dozen fires burning 100 or more acres Monday, with evacuations in place near several, including a 20,000-acre fire burning between Santa Rosa and Calistoga.
Napa County Fire Chief Barry Biermann said the fires had burned more than 68 square miles.
Ken Pimlott, director of the California Department of Forestry and Fire Protection, said the fires started around 10 p.m. local time Sunday.
The fires have been burning in northern Sonoma County since early Monday morning.
More than 200 people were hurriedly evacuated from Sutter Santa Rosa Regional Hospital and Santa Rosa Medical Centre, where the blaze could be seen raging nearby. He was one of hundreds of evacuees who streamed into a 24-hour Safeway market overnight, while authorities set up an official evacuation center.
Firefighters were battling a 200-acre (80.9-hectare) wildfire in Napa County, an area almost 70 miles north of San Francisco that is known for its vineyards, since late Sunday evening, according to the state Department of Forestry and Fire Protection.
"Our neighbor called and told us the sheriff had come - we had to evacuate now", he said.
"Everyone in Sonoma County is spread out fighting these fires, but they don't have enough resources to handle something like this". Kaiser Permanente Hospital in Santa Rosa evacuated patients. "I've gone out to get hold of news, which hasn't been much of a help", Palmgren said, as thick smoke surrounded his grandparents' Sonoma Valley home.
"Fire has burned all the way through the Silverado Country Club area", Biermann said in a reference to the Silverado Resort and Spa. "I mean blazing, falling down on fire". The Sonoma County Fairgrounds is open for people with large animals; access the fairgrounds via Gate 7 on Aston Avenue. KPIX reported flames near the Domaine Carneros winery.
Smoke from the fires drifted into San Francisco, Oakland and San Jose.