By Peter Schworm Globe Staff / April 8, 2010

REVERE BEACH — As if it were the heart of August, children splashed in the waves or lined up for ice cream, motorcyclists cruised the parkway, and Connie Person took to her oceanside beach chair and reclined with a book.

But it’s only April. At a time of year when Boston has seen blizzards, temperatures touched 90 degrees yesterday, shattering the 1991 record of 86. And after weeks of relentless gray and deluging rain, it brought sun-deprived souls streaking to the nearest stretch of sand.

“At last,’’ said Merle Saval, a 65-year-old from Stoughton. “We deserved this.’’

Saval and her husband, Jerry, got engaged on Revere Beach four decades ago, and yesterday they brought their young grandchildren there to bask in the unseasonably hot sun. Knowing New England springs, they had counted on an indoor day, maybe a movie or museum. Instead, the youngsters from Southern California enjoyed temperatures that were a good bit warmer than home.

The National Weather Service said the heat, along with winds that gusted up to 25 miles per hour, raised fears of brush fires, and meteorologists issued a red flag fire warning throughout the day for most of Massachusetts.

“The weather conditions are right that if there is a brush fire, there’s a greater tendency for it to spread because the burning conditions are better,’’ said Alan Dunham of the Weather Service.

The scorching weather also made it tempting to skip school, and a few hundred teenagers descended on Revere Beach around noon to celebrate the accelerated arrival of summer weather, strolling along the boardwalk and lounging on the sand, many still in backpacks.

To their dismay, police were out in force to greet them, having been tipped off to the truancy plans and wary of a repeat of last April, when some 3,000 hooky-playing students caused widespread disruptions. State Police were stationed along the boardwalk, and gatherings were subdued.

But beachgoers of all ages tumbled off the Blue Line around noontime, well supplied with iced coffee, light reading, and sunscreen. By 1, the strip was in midseason form, as crowds swarmed the beach and scantily clad figures of all shapes and sizes turned heads as they strolled along the strand.

“Good for the soul,’’ remarked Jerry Lurie, a 68-year-old from Chelsea. “This is what spring is all about. There’s a reason the birds are singing.’’

Even with the sun beating down, few dared to even dip a toe in the frigid waters. But some brave souls took the plunge.

“Summer has begun,’’ exulted Roger Beaulac as he air-dried after a dip. “For me, it’s now open season, no matter what the weather does from here.’’

A few minutes later, the 51-year-old from the North End waded out for a second dunk, drawing amazed looks from sunbathers and even scattered applause.

Up and down the beach, people cherished their moment in the sun, and the brightened moods that followed.

“I think this will take away all the rage in Massachusetts,’’ said Alice Miller, a 43-year-old from Reading. “After a brutal winter, this is just what we need.’’

The only somber note was the realization that the warm weather couldn’t last, but many grumbled at the mere suggestion.

“Don’t tell me that,’’ groused one young woman, who declined to give her name because she had called in sick to work yesterday morning, about “five seconds’’ after she heard the forecast.

Temperatures are expected to drop to the low-60s today, and a cold front could bring showers and scattered thunderstorms tomorrow morning. Cooler, more seasonable weather is predicted for the weekend.

The sudden hot spell caught many off guard, forcing regular beachgoers to shed their usual spring layers. “It’s been so cold,’’ said Mourad Aeeradi, a 27-year-old from East Boston, dressed in a sweater and jeans. “This is a very nice change.’’

Aeeradi, who moved here from Morocco in November, has struggled to adjust to the New England winter. But as he felt the warm sun on his face, he thought he had seen the worst. He walked slowly down the beach, as if trying to make the day last longer.

Some were so delighted by the unexpected warmth they felt a twinge of guilt for all their fist-shaking rants at the skies last month. If they had known a summer day was just around the corner, they would have let it slide.

“Isn’t it a shame we cursed all the rain?’’ Person asked from her oceanside perch. The question lingered in the breeze, and the sound of the softly lapping waves. In the sun, it didn’t seem that important, and she returned to her book.

Globe correspondent Shana Wickett contributed to this report.