Spring is a season of many gradual developments, but yesterday, it seemed, they all arrived at once.

There were many new things under the sun. The newest of all was the sun itself, returning from what must have been a visit to another solar system. Amid one of the coldest, wettest Aprils, benevolent air from the south nudged the temperature to a high of 82, and banished every memory of the rotten weeks that have kept Washington's traditionally matchless spring at bay.

Yesterday the natural progression of nature would not be denied as city life passed from the season of wool to the season of cotton in less time than it takes to lose a dry cleaning ticket or misplace an umbrella. The lunch-hour streets and parks were a pageant of picnickers, chess players and sunbathers replenishing their vitamin D, as people everywhere celebrated the novel beauty of an April day.

In Lafayette Square, the air smelled of fresh grass, and the red tulips encircling the tarnished statue of General Thaddeus Kosciuszko stood at the height of their brief, brilliant careers.

It was the first day in what seems a geological epoch in which you could enter a carry-out for lunch with the desire to carry lunch out. It was the first day in many where the rites of spring were in the air.

"You girls look just like the flowers," said a man in a suit, approaching a bouquet of working women who had kicked off their shoes, and spread their lunch on a blanket.

One of the woman turned to her companions and said, "Let me introduce you to my bus mate. Joe, this is Karen and this is. . . " Then, like an affirmation of the new possiblities, the chimes of St. John's Protestant Episcopal Church on H Street cut in, eight bells playing a tune called "Plain Bob Major," which organist Helen Penn said sounds "happier than hymns."

Nearby, Augustine Williams finished mowing the matchbook-sized lawn in front of Blair House. "If its nice, we work," he said with a big smile. "We lean with the wind." The tulips in his charge were beginning to droop and brown and curl, their beauty corrupted by time. They looked like aging actresses. Soon, said their caretaker, they will be supplanted by petunias and geraniums for the long hot haul of the summer. As for summer, said Williams, "I like cold weather, it's my own personal view. I can always put something on. But when it gets up into the 90s, I don't have anything I can take off."

Along the Potomac, out of the city, a red Jaguar convertible on the George Washington Parkway took the day in top-down style. The oaks wore fragile veils of budding leaves. The river, swollen with the incessant rains of the last month, raged a foot below flood stage, roaring so loudly at Great Falls that light conversation seemed absurdly strenuous.

"A week ago I would have been surrounded by linoleum," said Matt Dolan, a 22-year Bethesda student encamped with his Russian textbook on a rock overlooking one of the Potomac's thundering chutes. "This sure beats the buzzing fluorescent lights."

Nearby, Lucy the white goose and matriarch of Lock 20, basked in the attention of bread-tossing photographers, glad, one guesses, to be done with the past winter in which a dog had a mortal lock on her long white neck, and bruised it so badly that she couldn't hold her head up. But for the ministering of Pamela Brown, who with her husband, a park ranger, propped the goose's head on a pillow, Lucy would not have lived to see the spring.