Those twin scourges of a Washington summer -- wilting heat and insufferable humidity -- continued to afflict the inhabitants of the metropolitan area yesterday, proving once again that people have few things in common like miserable weather.

As the mercury climbed to a high of 96, one degree short of the record, families sat under elms on the Mall pining for zephyrs, kids ran their hands longingly across pictures of ice cream cones, and the only things that seemed fresh were the old cliches.

"We're Good-Humored out," sighed Norm Luce, a Cincinnati visitor strolling past an ice cream vendor at 15th and Independence with his wife and four bedraggled girls in tow. "I lost my good humor at 9 o'clock."

For those misfortunate enough to be outdoors with sweat streaming from pores, it was just the day to reflect on the fact that human beings are 70 percent water. If not that, then perhaps to sip a tall soft drink, chew the ice and revile the bureaucrat who decreed that District swimming pools shall not be open until Saturday.

The temperature climbed graudally throughout the day, starting in the morning at 80 degrees, which is extremely high for this time of year, 15 degrees higher than the normal early-morning low for nid-June. It crested just after 2 o'clock at 96 while the humidity hovered all afternoon between 50 and 65 percent.

The Virginia Electric and Power Co., which asked its custormers to turn off their electrical appliances, experienced an all-time peak demand late in the afternoon, surpassing a record set last Aug. 11. And the over-like temperatures forced many public schools in the Washington area to close.

But the worst of the heat seems to be coming to an end. Weather forecasters expect thunderstorms and showers Wednesday morning, accompanied by cooler temperatures in the mid-80s through Thursday.

Hot as it was, it wasn't hot enough to make Julian Morris want to jump in a tank of water with a lemon shark, a nurse and a green moray eel at the National Aquarium.

"If it were 500 degrees I would go in," said Julian, a student at St. Patricks school. "I'd jump right in and jump out."

The lemon shark, a species known for occasional attacks on man, finned past the nose of Julian and his classmate Vasili Datch on the other side of thick glass.

"I'd go inif I was dead," Vasili said, mopping his brow.

Porkfish and a friendly looking green sea turtle were swimming around in the next tank, much more hospitable as a prospective swimming pool.Vasili claimed he would go in then and there if he had a bathin suit. The boys exited past a Nassau Grouper, a lugubrious-looking reef dweller, and headed back to school with the rest of their class. "We're going to get ice cream and then our mothers are going to pick us up," Julian explained.

At the Boy Scout memorial pool on the Ellipse a block away, William Gilmore, a 25-year-old consultant from Wisconsin, had stripped off his shoes and was dangling his feet in the algae-laden water.

"I was going to go all the way in, but the water's a little funky," he said.

"If it were 10 degrees hotter out, I'd go in up to my neck."

The Boy Scout motto was inscribed on the plinth of the statue at the memorial, and, fittingly enough, the 12 boy scouts and their leaders from Troop 465 in Raytown, Mo., were sprawled nearby. The scouts had sacked and sold 6,000 pounds of pecans and cashews to pay for a two-week trip east. They didn't seem to be having any rpoblems living up to their Boy Scouts pledge to keep themselves "morally straight," but "physically strong" and "mentally awake" were other matters entirely.

"I'd like to be swimming in Hawii with 3,000 miles of waves coming in," Jeff Teeter, a 12-year-old First Class scout, whimpered in a wilted voice as beads of sweat seeped into his neckerchief.

"At Virginia Beach, they ran into the ocean, clothes and all, it looked so good," said scoutmaster Les Pierce. "They'd never seen the ocean before."

Not everyone was wringing their hands about the crummy summer climate hereabouts. William Hale, 50, a vendor who had piled his fruit on a board outside the Department of Commerce, was tipping back in a chair, looking as unflappably cool as ac Nassau Grouper.

"The heat don't bother me," he said, moving to the big band sound on his small transistor radio. "I don't need a hat 'cause I ain't ready to ride in that big black hearse. I can stand a lot of hugs and kisses yet. Wather like this I used to hit the ball on the gold course. I used to play with a lady who said 'You hit the ball better than my husband.'"

As the afternoon passed, Hale's daisies began drooping and his bananas turned brown in the hot sun, but he swigged on a can of beer and didn't seem to mind.