Summer Puts in a Searing Postseason Appearance : Weather: Temperatures soar into triple digits. Los Angeles, with 100 degrees, breaks record set in 1906.

After a summer of cloudy skies, foggy beach scenes and nonexistent tan lines, Mother Nature made a searing swing through Los Angeles on Tuesday, leaving behind a trail of record-breaking temperatures and sweaty, grumpy human beings.

The thermometer in downtown Los Angeles soared to 100 degrees, breaking the record of 99 set in 1906.

Throughout Southern California, temperatures surged into triple digits, reaching 101 in Burbank, 102 in Fillmore in Ventura County and a scorching 108 in El Cajon in San Diego County.

The mercury also hit 108 in Monrovia and soared to 105 in Van Nuys, 100 in Long Beach and Northridge, 102 in Montebello and 104 in Pasadena.

For most Southern Californians, the heat wave quickly became a test of stamina and resourcefulness.

Shoppers kept to shady sides of streets, lines of bus riders gathered in any available shade, office workers refused to leave their air-conditioned cubicles. That was bad news for Thousand Oaks hot dog vendor John Smiley.

“When it gets hot like this, I’ll probably eat more than I sell,” said Smiley, taking off his red golfing cap and wiping his brow. “People don’t even step out of their office.”

Huddled in a tiny patch of shade in the middle of an asphalt parking lot in downtown Los Angeles, attendant Felipe Aguilar contorted his face as he pointed to his enemy--a hardtop sedan, windows rolled up, vinyl upholstery and, ugh, a black steering wheel.

As beads of sweat dripped off his forehead, Aguilar demonstrated his plan of attack, sticking out two fingers as he pretended to barely touch the steering wheel.

“Aieeee!” he yelped, just thinking about getting in the car. “That’s hot.”

At Santa Monica Beach, where the afternoon temperature was a breezy 72 degrees, county lifeguards doubled their usual weekday staff of 15 to brace for the crowds. Lt. Nick Steers said he knew it was going to be hot inland when he awoke to clear skies.

“After 26 years of doing this,” Steers said, “you kind of eyeball it.”

The crowds started showing up around noon--”an extended lunch break,” he said. “We have a lot of people who are ditching their work, even some high school and college kids playing hooky from their appointed duties.”

At the State and Los Angeles County Arboretum in Arcadia, caretakers mobilized to give their 30,000 plants and trees an extra spritz.

“Most of our mature plantings are well adapted to the heat,” said Tim Lindsay, the arboretum’s associate superintendent. “Anybody who comes here will wilt themselves before the plants do.”

Caretakers of the exotic animal training compound at Ventura County’s Moorpark College were sent scurrying for their water bottles and hoses to make sure the 275 animals housed at the compound had enough water.

Jim Peddie, a college instructor and veterinarian, said pens housing large game cats were sprayed with cool water and most of the exotic birds spent the day in air-conditioned quarters.

Even Bobby the water buffalo, who normally detests being sprayed with water, wanted relief.

“If we spray him, he seems to resent it. It’s better to hose down the floor on his cage,” Peddie said. “It’s hot enough that any animal that’s outside is going to be bothered.”

Forecasters blamed the heat on a ridge of high pressure that parked itself over Southern California late Monday, making Los Angeles one of the hottest spots in the country, said Marty McKewon, a meteorologist for WeatherData Inc., a private firm that provides forecasts for The Times.

Those conditions are expected to remain in place today. Hotter-than-normal temperatures are expected to prevail through the weekend.

“If you’re looking for summer-like weather, it’s definitely in California,” said McKewon, noting that it has been rainy in the Southeastern United States and overcast in the Northeast.

Despite a fuzzy brown haze that hung over much of the Los Angeles Basin, air quality officials said the heat “literally blew the lid off” the inversion layer that normally makes such days as smoggy as they are sticky.

As long as the air above the inversion layer is warmer than the air below, the smog cannot rise, said Tom Eichhorn, a spokesman for the South Coast Air Quality Management District. But when it gets this hot, the air below breaks through and toxins dissipate into the atmosphere.

By midafternoon, the highest reading on the pollution standard index was 163 in Whittier, still in the “unhealthful” range, but short of the 200 reading for a first-stage smog alert.

The torrid conditions hampered firefighters as they battled a brush fire in Pasadena that left five houses slightly damaged.

“There were three strikes against us,” said Pasadena Deputy Fire Chief Don Hughs, who said the cause of the fire is still undetermined.

The fire broke out on a service road east of the Rose Bowl, encircling several houses on Richland Place and flinging embers as far as three blocks away. Two Pasadena firefighters were treated for heat exhaustion.

More than 150 firefighters from Pasadena, Glendale, Burbank and Los Angeles County had the fire under control within an hour.

While most Southern Californians spent the day complaining about the weather, some barely seemed to notice.

Kimberley Kim, the owner of Jake’s Famous restaurant in downtown Los Angeles, spent most of the day taking orders next to a 300-degree fry grill.

Kim, dressed in a sweater and red apron, was so busy she only managed to step away from the grill late in the afternoon. “Oh . . . it’s cool,” she said, marveling at the temperature outside. “This is the first time I’ve been cool all day.”

Times staff writers Edmund Newton and Psyche Pascual contributed to this report were