GUINDA, Yolo County (CBS SF) — Traveling at 1,000 acres an hour, the County Fire grew to 44,500 acres early Monday as it continued to force residents from their endangered homes in Napa, Solano and Yolo counties.

Cal Fire said the blaze — which roared to life in the rugged Rumsey Canyon area on Saturday — was just 2 percent contained but weather conditions had improved by early Monday morning giving firefighters renewed optimism that they could slow the fire’s advance.

Winds were shifting from the north to the west, dropping to 5-9 mph. With the west offshore winds came a dramatic increase in humidity to 43 percent and nearly 20-degree drop in temperatures.

Weary firefighters needed the break after a difficult weekend along the fire lines.

Frank Greer, who lives in the area of the fire, was mesmerized Sunday watching the aerial battle overhead.

“I haven’t seen this many choppers since I was in Vietnam,” he told KPIX 5. “They’re just going. Going like crazy here. (It’s) very reassuring.”

Cal Fire firefighter Craig Doppman summed up the tough challenge presented by the blaze.

“The conditions are really hard on the firefighters, but really good for the fire,” he said of the blaze’s rapid advance. “This is a lot of fire growth in very little time. It’s a very extreme fire.”

He was also thankful that the skies were filled with air tankers and helicopters.

“We’re using an air arsenal to cool things down,” he said “Trying to set retardant lines, and hopefully slow the fire.”

The fire grew overnight to 44,500 acres from 32,000 acres — more than the landmass size of San Francisco. Around 116 structures were threatened by the fire, which is burning near the east shore of Lake Berryessa. No injuries were reported and the exact number of people evacuated was unclear.

Autumn Edens marveled as a huge plume blocked the sun while she drove to her job as manager of the Corner Store in Guinda, a town of about 250 people just north of the fire.

“You can see the smoke and you can see an orange-red glow from the flames. It looks like a movie,” she said. “I’ve never seen a fire like that up close and it’s an intense feeling.”

It was one of two major wildfires in the northern part of the state, where temperatures were soaring, humidity was dropping and winds were steady.

A blaze burning for several days to the west in Lake County jumped containment lines Saturday, prompting additional evacuation orders. That fire was more than 70 percent contained after charring about 22 square miles (57 square kilometers) of brush and destroying at least 20 structures.

Smoke from the Yolo County fire was contributing to poor air quality in Napa, Sonoma, San Mateo and San Francisco counties, according to the National Weather Service.

The haze settling on areas to the south and west and rattled nerves near wine country communities that were devastated by deadly wildfires late last year.

“A lot of friends and family were texting today and saying they were having some PTSD,” said Savannah Kirtlink, who evacuated her Napa home during the blazes in December. She took photos of the smoke moving in this weekend and told KGO-TV she empathized with her neighbors to the north who were forced to flee their homes.

“I’m imagining what they’re going through,” she said.

A dusting of ash fell as far away as San Francisco, where tourists snapped pictures of the Golden Gate Bridge enveloped in an orange shroud of fog and smoke.

Across the bridge in Marin County, some customers coughed as they stopped for gas at the Shell station in Sausalito, employee Sergio Garcia said.

“The sky is very dark, even in the middle of the day,” he said. “It’s a little scary.”

Officials urged people not to call 911 about smoke unless they see actively burning fire.