(Reuters) – Firefighters in drought-hit California who are battling a 50-square-mile wildfire could be hampered by triple-digit heat, wind gusts up to 30 mph and low humidity on Tuesday, according to the National Weather Service.

About 3,000 firefighters have been fighting to contain the so called Sand Fire on the rugged northwestern fringes of the Los Angeles National Forest since Friday.

The blaze has killed one person, found in a burned-out car parked in a driveway, and destroyed at least 18 homes. An estimated 20,000 to 30,000 people were forced to evacuate but late on Monday, fire officials lifted the evacuation order for the majority of residents.

The fire was just 10 percent contained on Monday evening as crews backed by bulldozers labored to hack buffer lines around its perimeter as it cast a pall of smoke and soot over a wide area.

An air quality advisory was in effect in the area of the fire until Tuesday midnight local time after much of the Los Angeles basin was dusted with a thin layer of fine white ash from the fire over the weekend.

Among the properties to go up in flames was the landmark Sable Ranch, a popular location for television and movie shoots.

About 300 miles to the north, another fire ravaged a hilly area near the scenic coastal city of Carmel-by-the-Sea, churning through 16,100 acres (6,500 hectares) and destroying 20 homes, authorities said.

The so-called Soberanes Fire, burning in the Los Padres National Forest in Monterey County, threatened 1,650 structures by Monday evening and was only 10 percent contained, the U.S. Forest Service said.

The causes of the two fires were under investigation. They are among some 3,750 blazes large and small to have erupted across California since January, a higher-than-normal total, collectively scorching more than 200,000 acres (80,940 hectares), state fire officials said.

The biggest so far was last month’s Erskine Fire, which consumed 48,000 acres (19,429 hectares) northeast of Bakersfield, killing two people and destroying about 250 structures.

By comparison, the 2003 Cedar Fire ranks as the biggest on record in the state, burning more than 273,000 acres (110,480 hectares) and killing 15 people.

(Reporting by Brendan O’Brien in Milwaukee; Editing by Raissa Kasolowsky)