1st degree burn

Parasols were plentiful on local beaches. Ice cream became a ubiquitous refuge. Sweat seemed to stain anything worn or touched by anyone outside for more than a few minutes.

With the temperature reaching 89 degrees and the humidity surging, yesterday was the hottest day on record this summer.

Oddly, the last time Boston experienced such heat was in the spring, when the temperature reached 92 degrees on May 21. But that blip of warm weather lacked the oppressive humidity that made the city swelter as it did yesterday. The heat index made it feel like 95 degrees, according to the National Weather Service.

“It really feels like Florida today,’’ said Mary Amicangelo, 86, of Bradenton, Fla., while looking after her great-granddaughters in the shade of a copse of trees on Castle Island. “It has that heat that sort of envelops you, and you can’t get away from it. It draws all your energy and makes you yearn for air conditioning.’’

A few miles away, Colleen Ward sat beneath a large umbrella, looking at the placid water off Carson Beach.

“It’s really hot,’’ muttered Ward, 17, a lifeguard whose pale skin had turned increasingly red as she watched a few children wade into the water. “But it’s better than it has been.’’

The sudden appearance of summery weather made it more tolerable for many people, especially those who work outside.

“Much better than working in the rain,’’ said Ryan Mahoney, 29, an engineer overseeing construction of a new park along Fan Pier, who survived the deluge that didn’t seem to stop for much of the past two months and led to one of the wettest, coolest Junes on record in Massachusetts.

Luiz Santos, a mechanic at a gas station on Cambridge Street, said he had gulped down eight large cups of water by 2 p.m.

“When it’s muggy, it’s a lot harder to work,’’ he said from inside the station’s garage, where a fan blew on full blast. “It makes you drag a lot more, but I’ve seen it worse.’’

ISO New England, which runs the region’s electric grid, said preliminary numbers made yesterday the top energy-demand day of the year. An ISO official put the number at 22,883 megawatts, pushing past 2009’s previous high, set on Wednesday.

Some did more than tolerate yesterday’s conditions, expected to dissipate today, when a high is expected in the mid-80s. Drier air should arrive Wednesday, when the temperature will peak at 77 degrees, forecasters say.

Keagan Bozicevich and his three brothers were ecstatic as they jumped around the new fountains squirting out of the pavement along the Rose Kennedy Greenway. They took turns making rockets out of the fountain by putting bottles over the holes in the pavement and watching them shoot skyward with each burst of water.

“It’s pretty sweet,’’ said Keagan, 10, whose family was visiting from Minnesota.

A block away, Gordon Romer slurped the melting remains of his vanilla ice cream while he waited for a table at a restaurant overlooking the harbor.

“It’s not too bad,’’ said Romer, 54, who lives in downtown Boston. “It’s just nice to be able to be outside.’’

Michael Coughlin and Andrew Khederian, who give rides to tourists for Boston Pedicab, were happy to be sweating. “It feels like all the rain we’ve had made everyone soft,’’ said Coughlin, 28. “. . . For us, it’s good that people prefer not to walk as much. That makes us happy.’’

Unfortunately for Inga Grote and her boyfriend, the rickshaws were too far away.

The 24-year-old from Germany sat on a shady stoop with her boyfriend near the top of Beacon Hill, both exhausted from tramping around the city all day. They took off their shoes and guzzled their water.

“It feels like we’re in the tropics,’’ Grote said. “We don’t feel like moving anymore.’’

David Abel can be reached at dabel@globe.com.