Record Heat Sends Thousands to Beaches : Weather: Rip currents keep lifeguards busy with rescues. Temperature hits 89 degrees at El Toro.

Record-breaking heat and hazy skies sent nearly 400,000 people scurrying to Orange County beaches Sunday for relief. Once they were there, lifeguards said, warmer-than-usual waters and rip currents led to as many rescues as on the busiest summer days.

“We’ve had close to 80 rescues so far and we’re still making them,” Huntington State Beach lifeguard Clark Griffith said in late afternoon. At least 50,000 people packed the sand and surf there, and Griffith said, “it’s a lot busier than last Fourth of July.”

Nearly 70,000 people jammed three miles of Huntington Beach’s city shoreline. “We’ve got a whole city down here,” said Mike Bartlett, the city’s lifeguard supervisor.

In neighboring Newport Beach’s 5 1/2 miles of surf, lifeguards made 75 rescues among a crowd of at least 130,000.

“This is even crowded for a summer weekend day,” remarked Newport Beach marine safety officer Josh Van Egmond.

Despite the hectic pace for lifeguards, however, no serious accidents were reported throughout the day off Orange County’s shores.

Few beach-goers showed much interest in packing up their towels and heading for home even as the sun began to dip below the horizon, said Newport Beach Marine Safety Officer Mitch White.

“I can still see hundreds of people out there playing in the surf,” White said at almost 7 p.m. “Our lifeguards want to go home and have a cold one, but we can’t let ‘em leave.”

Indeed, the mercury topped out at 89 degrees Sunday in El Toro, breaking the previous county record of 84 degrees for the date, set in Anaheim on April 26, 1969.

Santa Ana was not far behind with a high of 88 degrees, and Fullerton topped off at 87 degrees, according to the National Weather Service.

But the heat didn’t help local air quality.

There was little wind to blow away the pollutants cooked up by the heat and by hundreds of thousands of cars jamming roads to the El Toro Air Show and area beaches. As a result, the South Coast Air Quality Management District posted a health advisory for North County for a few hours in the early afternoon.

Unseasonably hot weather is likely to stick around at least through Tuesday, except for some low clouds and fog along the coast during the early morning and late night hours.

Steve Burback, a meteorologist for WeatherData Inc., which provides forecasts for The Times, said a high-pressure ridge centered in the upper atmosphere over California and the Southwest has allowed the deserts of California and Arizona to heat up, creating a thermal low-pressure system that has bottled up weather patterns across most of Southern California.

“This is the kind of effect we would normally see in the summertime, usually around August,” he said. “But it’s going to change by the latter part of the week. By Wednesday or Thursday, it should break down.”

Despite the lightest of winds, boaters were out in force off the Orange County coast Sunday.

“There’s a lot of people maneuvering out there in the harbor and there’s not a lot of room,” said Sheriff’s Sgt. Andy Decker at Newport Beach Harbor, where the high temperature was 75 degrees.

Harbor Patrol officers were kept busy responding to a flurry of boating collisions, but most were minor at speeds of less than 5 m.p.h., Decker said.

In Laguna Beach, a crowd of about 45,000 beach-goers equaled the city’s busiest summer weekend day, said lifeguard Scott Diederich. “It’s pushing our limit,” he said.

No one was seriously injured in any of the beach rescues, but lifeguards attribute the unusual number in part to warmer-than-usual water temperatures of about 70 degrees, which brought more people than usual into the springtime surf. Add to that equal parts of inexperience, bravado and a shoreline shifting with the seasonal change in ocean currents, lifeguards said, and the result is a busy day of rescues.

Times staff writer Lynn Smith contributed to this story.