A Listless Summer Builds Up Some Steam : Weather: Coastal cooling is expected after tropical heat. Fire officials are hoping for more mugginess.

When Arlene Muir drove to her job in Costa Mesa on Tuesday, gone were the dreary morning clouds that typified Orange County’s summer of 1991.

Instead, Muir donned sunglasses, “for the first time in months,” she said, as she and others baked in unusually warm and muggy weather.

“Everybody who comes in has been complaining of how hot and sticky it is,” said Muir, a clerk at Conroy’s flower shop on Harbor Boulevard in Costa Mesa, where the mercury zoomed to 80 degrees by 8 a.m. on Tuesday.

Peak temperatures in Orange County were again in the high 90s. Santa Ana reported 98 degrees, just two degrees shy of a record. Anaheim also had a 98 and Newport Beach got up to a steamy 94 degrees.

But Tropical Storm Hilda, which was reduced to a tropical depression, was expected to leave Southern California by today after dropping a light rain in Costa Mesa on Tuesday night. No other cities in Orange County reported rainfall.

Instead of sweltering in 90-degree temperatures, Orange County residents today will see a vaguely familiar pattern: morning clouds and clearing by the afternoon, said Steve Burback, a meteorologist with WeatherData Inc., which provides forecasts for The Times.

“You should expect a drop of 5 to 10 degrees in the coastal areas, but inland areas should remain the same. Look for a return on the coast of clouds and coastal breezes,” Burback said.

Hilda, which brought scattered showers and sent temperatures near the century mark, also churned up waves of 3 to 5 feet on the coast and prompted thousands in the Southland to switch on air conditioners.

Steve Hansen, a spokesman for Southern California Edison Co., said customers used 15,685 megawatts on Tuesday, 18% more than on Monday. The power company’s all-time peak demand was 17,647 megawatts set June 27, 1990.

But the sticky mugginess pleased Orange County’s firefighters.

“The humidity is excellent because our burn index has been down. In fact, the running comment among firefighters at a meeting today was that it would be great if we could have two or three tropical storms and then go right into the September rains,” said Capt. Dan Young, a spokesman for the Orange County Fire Department.

The burn index is a numerical figure that takes into account heat, humidity, wind and other factors.

“If the index is over 60, our fire condition is critical. If 40, it’s moderate and 30 is a low risk. But the last two days we’ve had it in the teens,” Young said. “And boy, that’s been really nice.”

Hilda also sent thousands of people to Orange County beaches Tuesday. However, overall attendance at Orange County beaches this summer remains the lowest on record.

In San Clemente, Seal Beach and Newport Beach, beach attendance plummeted during the cool, cloudy months of June and July.

Officials in San Clemente said that in June, 197,900 people went to city beaches, compared to 242,200 in June, 1990. This July, San Clemente beaches logged 292,400 visitors, compared to 426,000 last July.

“Everybody has noticed the decrease,” said Steve Lashbrook, a marine safety officer for San Clemente. “We’ve cut back our (lifeguard) staffing, especially during the weekdays, because of the decrease. People have seen clouds all summer long; it’s been dreary.”

Only in Huntington Beach, say city officials, have beach crowds actually increased, despite construction of the city pier, said Ronald Hagan, Huntington Beach community services director.

“We had more special events in 1991 than last year. That means we had more day camps being held on the beach by a lot of churches and groups. Plus we also had the Op Pro (surfing) contest held in July rather than August, and we helped sponsor a junior lifeguard state competition,” Hagan said.

Hagan said attendance for July was 1.2 million, compared to last year’s figure of 812,123.

Although more people went to the beach, July’s cold weather caused food service among concessionaires to dip by as much as 40%, Hagan said.

“When you don’t get a lot of people going down to the beach and sitting by fire rings, it hurts from a concession standpoint. Food service and parking revenue were down for July,” he said.

Uncrowded Beaches Bad weather has kept people away from the beaches this summer. But Huntington Beach has bucked the trend, with activities such as Op’s annual surfing contest and a summer day camp drawing people to the sand. Figures shown are for the month of July. Seal Beach 1990: 280,000 1991: 190,000 Huntington Beach 1990: 812,000 1991: 1.20 million Newport Beach 1990: 2.16 million 1991: 1.68 million San Clemente 1990: 426,000 1991: 292,400 Source: Individual cities