LOS ANGELES — A wildfire that for days has threatened hundreds of homes and popular seaside campgrounds near Santa Barbara was half-surrounded and held in check, though firefighters were about to face the hottest day yet and the kind of dry, torrid conditions prevailing from the West Coast all the way to New Mexico.

A Red Flag warning for late Sunday and early Monday, signaling dangerously dry heat and high winds, was declared for the hilly coastal area west of Santa Barbara.

The fire was 51 percent contained after burning more than 2 square miles since starting on Wednesday.

Meanwhile near downtown Los Angeles, a small-but-dangerous brush fire threatened a densely populated, hilly neighborhood along a freeway amid sizzling temperatures Sunday.

Crews knocked down the blaze in the Silver Lake neighborhood after it damaged two homes, destroyed three shed-like structures, scorched yards and sent trees up in flames.

Neighbors scrambled with garden hoses and buckets, while water-dropping helicopters and scores of firefighters chased embers and doused steep hillsides to keep the flames from spreading.

The blaze only charred 8 acres but gave urban residents a scare.

Paul Gaffner had been swimming at a pool a few minutes from his home and was planning to run errands when he saw heavy smoke near his house.

“Man, that fire is at my house,” he said he thought.

When he arrived, his neighbor was hosing down flames in his backyard. In his flip-flops and shorts, he joined the fight as neighbors chipped in help protect their houses.

“It was a lot going on,” Gaffner said as he handed out bottles of Gatorade to firefighters. “You’ve got it in front of you, you don’t have time to panic.”

Another wildfire that broke out Sunday forced the evacuation of about 75 people from a tiny town in the California desert near the Mexico border.

It had surged to over 2 square miles amid triple-digit temperatures near the town of Potrero, a ranching community just a few miles north of Tecate, Mexico, and about 40 miles southeast of San Diego.