More than 2,500 acres had burned by early Tuesday, and officials were hoping that lower temperatures and increased humidity would aid in their efforts, said Joe Tapia, a spokesman for the California Department of Forestry.
Officials also were urging residents of about 50 homes to leave the Cohasset area north of Chico, where a blaze had burned more than 1,000 acres and destroyed one home.
Residents found shelter with family and friends. By late Monday night, no one was at an evacuation center set up at Pleasant Valley High School, Red Cross officials said.
But earlier in the day, Anne De Felice, 38, of Cohasset took refuge there.
"We didn't insure it [her home] for that much because it's an old trailer, so if it burns, we're homeless," she said. "But I trust in God. He'll take care of it."
More than three dozen other lightning-caused blazes were burning in Butte County. The lightning, some of it without rain, swept through the area starting fires beginning early Monday morning.
Several other small blazes were burning in Shasta, Tehama and Lassen counties, officials said.
One firefighter battling the Cohasset blaze suffered heat exhaustion, and another was slightly hurt when the engine he was riding in collided with an 18-wheel truck on a Chico city street, Tapia said. The truck driver suffered moderate injuries.
Three other firefighters were transported to an area hospital Monday afternoon to be treated for heat-related injuries from battling the blazes, said California Department of Forestry spokesman Wayne Kyle. He did not have additional information on the nature of their injuries.
Tapia said there was no estimate on when the fires would be contained.
"Temperatures are dropping and the humidity is coming up [and there is] light wind. That'll assist us in making good progress on the fires," Tapia said.