Struck by the sun and deadened by the dense, damp air, Washington seemed to be moving in slow motion yesterday as everyone tried to find some way of coping with the heat or trying to take advantage of it. It was the first day of a real Washington summer, and nature and the city's residents were falling into their accustomed patterns.

At National Airport the temperature a reached 94 degrees, the hottest it has been this year. The humidity hovered around a sticky 50 percent and the air quality index registered an "unhealthy" 105.

"It looks like that long, pleasant spring is over," said Chet Hendrickson of the National Weather Service. "I'm sorry."

At 17th and Euclid streets NW, Ricardo Cash and some friends stood idly next to a wall on which someone had spray-painted "Wash ... Getto." In Cash's neighborhood, air conditioners are scarce. "You just stand in the shade. Stand in the house. It's too damn hot," said Cash. "About all you can do is go down to the park."

Across the street, Katherine Washington was spending her afternoon watering neighborhood children with a leaky hose. Two-year-old Tara Bennett, in falling-down red shorts and a white bathing cap, shivered with joy as the water hit her. Other children lay down on the sidewalk in the puddles only to get up running and screaming when a fresh shower descended on them.

"The swimming pool they usually go to (at Marie Reed Community Learning Center) is closed today," Washington said. "It's terrible. I can't stand heat. As soon as we can we're going down by the water - Hains Point or Anacostia - take a blanket and just lay down there."

At a garden party on Georgetown's Cambridge Place, the heat and humidity were just as oppressive, though there were, of course, compensations. Guests snacked on strawberries dipped in powdered sugar, ate pate and *drank chilled wine.

"Well," said Myra Buvinic, who is visiting Washington for a conference, "if you've got to be hot, this is the place to do it."

Madras jackets and blazers were shed and piled in a closet (ties were never a factor), but still there was no getting cool, even in the shade of a spreading crab-apple tree.

"Standing still might do it." ventured David Gislin of the National Academy of Sciences. Spots of sweat were breaking out through his short-sleeved shirt. "But if you stand still you can't get the air moving around you." He stood still anyway and sipped his wine.

"Sweating is - quoting Jane Austen I believe," essayed one young woman, "Sweating is so inelegant."

At the Ontario Theater in Adams-Morgan there are weekend matinees of Spanish-language films, and manager Jose Rosario said a lot of Latin Americians come to get together "like in a community center," and to escape the heat. "A lot them bring in little bags with sandwiches, Cokes ... et cetera, and they stay all day."

Yesterday there was a crowd of about 200 to see "La Muerte de unGallero" - The Death of a Cock-fighter" - and to keep cool.

Coountless families were braving the heat to got to the National Zoo.

The Great India rhinoceros stood in water up to his horn. A beleaguered African elephant was trying unsuccessfully to batter his way into the cool of his cage. The white tigers looked too tired even to dive into their pool full of coins. And, of course, the pandas slept in air-conditioned comfort.

Nathaniel and Phyllis Laney and their three children sat, meanwhile, on a bench in the shade, looking near exhaustion.

"What can we say about the heat?" asked Mrs. Laney.

"Nothing that would change it," said her husband.

Noting that it was Father's Day, she commented, "I do wonder what's the treat for fathers here."

"Punishment - makes you feel like a father."

Despite the heat, some people insted on their weekend regimen of activity. Shirtless bicyclers cruised the streets (though joggers were notably few and far between).

On the Mall, track shorts and cut-offs were out in force, softball games were underway, volleyball players leaped and scrambled, while polo players charged back and forth like small-bore cavalry.

At the public tennis courts near 34th Street and Voltra Place NW, people were waiting hours for the chance to bash a ball back and forth under the sun.

"We crashed our way onto some courts this morning." said lawyer Ede Holiday, "and we're playing again at four."

In the meantime she and her colleague Mary MacArthur were lying on the grass in their bikinis, working hard on their suntans.

"What can you say?" said Holiday, "The batteries are running down on your radio, you're getting to the end of your book - sweating - just your average lazy Sunday afternoon."