Wet weather and cooler temperatures helped over 5,000 firefighters battling the King Fire to 18 percent containment over the weekend.

The fast-moving blaze--located 60 miles east of Sacramento--has claimed nearly three dozen buildings since Sept. 13 and burned an estimated 87,592 acres near Pollock Pines, according to a California Interagency Incident Management report released Monday morning. Preliminary figures released by CAL FIRE show 10 residences and 22 outbuildings being destroyed.

View California Fire Map in a larger map

A vital University of Berkeley research station that houses numerous trees, plants, and wildlife is also threatened by the largest wildfire ever recorded in the Sacramento region.

Fire crews will focus on the un-contained northern side Monday where capricious winds threaten to escalate fire activity. Falling timber also poses risks to crews constructing control lines through the dry terrain.

"The fire may become very active today with the return of high temperatures and lower humidity. The spread is expected to be predominantly towards the northeast due to the southwest wind," CAL FIRE posted to a Facebook page made solely for King Fire.

Poor air quality forced several school closures in the area and the cancelation of Ironman Lake Tahoe events minutes before their Sunday start time. In addition, the National Weather Service in Reno has issued a dense smoke advisory, which runs from 11 a.m. to 8 p.m.

Of some 2,800 evacuees, only about 100 have been allowed to return home.

The American Red Cross is collecting donations to assist residents directly impacted by the King Fire. Donations can be made at RedCross.org, by mail, or at 1565 Exposition Boulevard, Sacramento, CA 95818.

Authorities have arrested 37-year-old Wayne Huntsman on suspicion of arson. The Pollock Pines resident pleaded not guilty at his arraignment Friday and is being held in El Dorado County Jail on $10 million bail.