The Day fire, which had burned nearly 48 square miles in Los Padres National Forest and a small area of the adjoining Angeles National Forest, slowed to a crawl Thursday as humidity rose and temperatures fell. Crews had it 30 percent contained, the U.S. Forest Service said.
The weather was expected to remain cool and moist Friday. Firefighters were trying to carve or improve fire lines all around the blaze in case hot, dry Santa Ana winds, which were expected to begin on Sunday, forced them to retreat.
The cooler weather has allowed hand crews to get close to the flames without the risk of being overrun. They were flown into inaccessible terrain Thursday to tackle problem areas, said fire Capt. Glenn Skaggs of the Angeles National Forest.
"The big push is the next 48 hours," Skaggs said.
About 1,700 firefighters were assigned to the blaze, which nearly doubled in size this week because of hot weather. The firefighting cost has risen to $13.1 million.
Meanwhile, the fire threat remained extreme in other areas of the West. On Thursday, the state Forestry Department suspended burning permits, barring the use of open fires on state lands in San Diego and Imperial counties in California, except campfires in established campgrounds.
The 30,639-acre blaze was burning brush-choked canyons and ridges west of Interstate 5, the main highway linking Los Angeles with San Francisco. Although it once threatened to jump the highway, on Thursday it remained a mile or so from a mobile home park on the other side.
The Paradise Ranch park was not in immediate danger and no evacuations were ordered.
The interstate had all four northbound lanes open early Friday, with traffic restricted to three southbound lanes in the area of the fire. It has been closed sporadically since the fire began on Labor Day, sparked by someone burning debris.
Cabins, campgrounds and a ranch have been evacuated because of the 2000-acre-plus Cigarette Rock fire burning near Augusta, Montana, west of Great Falls. Fire officials say the fire is burning timber, brush and grass in the Lewis and Clark National Forest.
Another blaze, the Jungle fire, is burning in timber in the Gallatin National Forest east of Bozeman, Montana. More than 300 homes and cabins have been evacuated.