âThis is really serious. Itâs moving fast. The heat, the lack of humidity and the winds are all driving a very dangerous situation and making it worse,â the governor said at a morning news conference. âItâs not under control by any means. But weâre on it in the best way we know how.â
The fires began at about 10 p.m. Sunday and were fanned by wind gusts moving faster than 50 miles an hour, Ms. Upton said. The cause remained under investigation on Monday afternoon.
The worst fires in Northern California tend to hit in October, when dry conditions prime them to spread fast and far as heavy winds, known as north winds or diablo winds, buffet the region.
Ms. Upton said that conditions were critically dry, given the lack of moisture in the air and the buildup of grass, brush and trees.
âCombined, thatâs a recipe for disaster,â she said.
Smoke billowed into the Bay Area, but the Marin County Fire Department reported that there were no separate fires in the area.
Reports suggested that residents in the region were caught unaware, many of them fleeing the area in cars and on foot as firefighters rushed to contain the outbreak. A number of roadways, including highways, were blocked by fire.
Neighborhoods in Santa Rosa, the county seat of Sonoma, were evacuated, according to the city manager, who said the Kaiser Permanente and Sutter hospitals were being cleared out. Flying cinders carried the fire across roads and ignited small patches of fire through neighborhoods: A pile of wood chips in the Home Depot parking lot caught fire.
Traffic lights at multiple intersections in Santa Rosa were not functioning. Columns of black smoke could be seen in the evergreen forests on the northern outskirts of the city.
The fires raged through the hills that are home to some of the countryâs most prized vineyards. The main north-south highway that connects San Francisco to the northernmost parts of California was closed Monday as fire engulfed both sides of the freeway. Santa Rosa is a hub for tours into wine country. At least two large hotels that cater to the wine tourism trade were destroyed by the fires.
North of Santa Rosaâs downtown, residents of the Overlook, a hilltop apartment complex, used fire extinguishers to put out flames engulfing cypress trees planted along a building. Minutes later, the flames returned. At least three engines and ladder trucks arrived but could not stop flames on one of the buildings from spreading to the roof.
âIt looks like theyâre giving up on that one,â said Derek Smith, a Santa Rosa resident watching the blaze whose house was several blocks away.
Lisa Kaldunski, an operator at Sutter Santa Rosa Regional Hospital, said around 6:30 a.m. local time that the facility was being evacuated and that patients were being taken to other hospitals.
Marc Brown, a spokesman for Kaiser Permanente, said about 130 patients had been evacuated from the Santa Rosa medical center because of the fires.
The Lake and Mendocino County sheriffsâ offices ordered evacuations. The Butte County sheriff announced that there were two fires in the area and listed neighborhoods where evacuation was mandatory.
Belia Ramos, the chairwoman of the Napa County board of supervisors, said the county was dealing with three main fires. One has threatened more than 10,000 acres in northern Napa County, another has endangered 8,000 to 12,000 acres, and a third has affected about 2,000 acres, she said.
California was hit by fires throughout the summer. Late last month, several blazes led to the evacuation of about 1,000 people in Southern California.
âIâve been with the department for 31 years and some years are notorious and theyâre burned in your memory,â Ms. Upton said. âIâm afraid that 2017 is going to be added to that list now.â
Even into the early afternoon â many hours after the homes were destroyed in the Journeyâs End retirement community in Santa Rosa â flames shot from a large propane tank with a roar that resembled an aircraft engine.
Richard Snyder and Robert Sparks, both residents of the retirement community, said their neighboring trailers were incinerated. They lost televisions, books, laptops â and copies of the insurance policies that they had taken out.
âThis is all I have,â Mr. Snyder said, pointing to his jeans and turquoise T-shirt. âAnd one pair of glasses.â
The fire was so intense it burned through the metal and glass trailers and safes that were advertised as fireproof.
âIt was locked,â Dana Walter, Mr. Sparksâs daughter, said of the safe. âPassports, ID cards, everything gone.â
Ofelia Razo, one of about a dozen residents whose houses were spared, fled her house with her purse in a pre-dawn evacuation with dozens of other residents. Her husband, Milton, took only his guitar. The flames were visible in the hills across the street from the retirement community.
When they returned around 10 hours later, Ms. Razo saw the smoking rubble in the distance and broke down.
âI started crying,â she said.
As she came closer she saw that the fire had stopped at her wooden lattice fence. Her powder blue trailer had been bizarrely untouched. Even the plastic flowers in a ceramic pumpkin vase on the porch were intact. Her red rose bushes were only lightly singed.
âItâs a miracle!â she said. âGracias, SeÃ±or!â