One fire had spread across nearly 6 square miles in Napa County and quickly moved into a mostly rural area of Solano County. The fire threatened more than 100 buildings as it fed on grassy woodland about 40 miles southwest of Sacramento, said Roger Archey, a spokesman for the California Department of Forestry and Fire Protection, or Cal Fire.
It was 40 percent contained Monday morning and had destroyed one home, officials said. Evacuations were ordered for some residents, said agency spokeswoman Nancy Carniglia.
CBS News affiliate KPIX-TV reports that while cooler temperatures have helped, high winds and lightning have created additional challenges for the fire fighting efforts.
"Because of the rough terrain up there, it's very difficult to establish a very solid line," California Department of Forestry & Fire Protection Battalion Chief David Shew told the station. "Unfortunately as everyone knows, we have lightning strikes that have affected all of Northern California right now, so our resources are at a very thin level."
Firefighters in southern New Mexico, meanwhile, were trying to stop a 43,000-acre wildfire that's destroying grazing allotments since starting in the Lincoln National Forest, a U.S. Forest Service fire information officer said.
Two other lightning-sparked wildfires also have burned nearly 30,000 acres. One was burning west of Roswell in southern New Mexico, and the other was west of Raton in the northern part of the state.
Wildfires have destroyed more than 175 homes in Northern California so far this year. Blazes started popping up in the region just as California's unofficial fire season began in mid-May, following the state's driest two-month period on record.
Two blazes about 25 miles south of San Jose also forced several residents from their homes. The fires covered about 2 square miles.
Officials said one fire was 90 percent contained Monday and the other 50 percent contained. Many residents were being let back into their homes.
Thunderstorms were responsible for as many as 75 fires in Shasta-Trinity National Forest, about 160 miles north of Sacramento. They ranged in size from less than an acre to more than a square mile. None immediately threatened homes, said Forest Service spokesman Michael Odle.
Mendocino County had as many as 90 fires, charring a total of 5,000 acres, Cal Fire officials said.
South of San Francisco, a fire that started Friday in Santa Cruz County and destroyed homes and closed a stretch of highway was contained after charring just less than a square mile. Evacuation orders were lifted Saturday, a day after roughly 2,000 people fled their homes.
It was the third major blaze to hit Santa Cruz County in the past month. A 520-acre blaze destroyed 11 buildings in the Santa Cruz Mountains, and a fire near Corralitos covered more than 4,200 acres and destroyed about 100 buildings.
Meanwhile, residents in Brisbane, a small city just south of San Francisco, were being allowed back into their homes after a grass fire scorched several hundred acres on San Bruno Mountain.