A holiday mood caught the city yesterday as the first day of November brought with it a touch of the summertime warmth that should have been by this time of year just a memory. Temperatures soared to 82 degrees, four short of the record high for the day.

People celebrated with picnics beside the river, bicycle rides and runs along the towpath and around Hains Point, afternoon naps taken in the warm grass of small urban parks where roses still bloomed. The weather inspired painters who brought their easels out of doors and romantics who bought wine, and in one case, balloons, to go with lunch.

Upon awakening yesterday, Michael Lambert thought to himself, "This is a good day to go down to the river." Fortunately, his boss, National Home Study Council Executive Director William Fowler, readily agreed. They left their office near Dupont Circle and headed for Fletcher's Boat House, stopping along the way for a bottle of German wine, a loaf of French bread, cheese, apples and Pepperidge Farm Irish oatmeal cookies.

In a generous mood, the two would have gladly shared with other picnickers. But they had, alas, brought only two cups. As they ate on a bench, the sun danced on the river, where the cattails rustled in the breeze and a fisherman in a white cap sat hunched over his line in a wooden rowboat. Across the river, the trees burned in autumn colors of gold and red. Lambert sipped his wine, a contented man.

"This reminds me of Renoir's Boating Party," he said.

How long did they have for this repast? Fowler, the boss, grinned. "Til we get back."

At the next picnic table, Paul Ambrogi, an account executive for a printing company in Cheverly, ate a considerably more modest lunch, centered around a baloney sandwich and a can of grape soda. His briefcase was open, his legal tablet before him. "I walked out of a client's office after a two-hour meeting this morning feeling totally drained," he said. "I said to myself, 'I've got to get down to Fletcher's and enjoy the weather.' "

His wife, noting the splendor of the day, had telephoned him earlier from their Gaithersburg home. "She said, 'Why don't you take the rest of the day off?' It would have been nice, but I don't have the time . . . I'm an ambitious person. What do I want? To be rich and famous."

In the heart of the city, a small lunchtime crowd gathered at the Columbia Historical Society's little garden park, hidden between tall office buildings and an ivy-covered stone wall at 19th Street and Sunderland Place NW. A few red roses still clung to their stems, and the grass was warm enough that a young red-haired woman in a T-shirt and long paisley skirt could lie on her back and sleep, apparently oblivious to the sounds of construction work on nearby streets.

The average temperature here for Nov. 1 is a considerably cooler 54 degrees, according to the U.S. Weather Service. Forecasters said the unseasonable weather was brought by a high pressure system along the East Coast and would continue through today.

Artist Vivian Matz, who was painting the towering oak tree in the middle of Dupont Circle while listening to Squeeze through the headphones of her Sony Walkman, described the day in her own way. "It's like a bowl of Froot Loops." She took off her headphones for a moment to exult: "I see yellows and browns and reds and maroons. The reflection of the light off the colors is really beautiful. It's a departure from hard-core reality."

This being Washington, Dupont Circle also was the spot yesterday for lawyer Ken Trombly to prepare for an upcoming personal injury case by studying the Associated Lawyers of America Law Reporter. But the lawyer in the gray wool pinstripe suit could be seen sneaking frequent glances at Matz's progress.

On the grass nearby, engineer Michael Rau had succumbed to the spirit of the day by presenting his friend Liz Correa with three balloons -- one red, one green and one white painted with a set of red lips.

The warm weather gave bodybuilder Wayne Cooper a chance to show off his physique. In white shorts and no shirt, with a jumprope knotted at his waist, he paraded down Pennsylvania Avenue, a proud and happy man. "I feel great today," he said. "I feel great every day."

Such weather can't last in November, and it won't, according to forecasters at the U.S. Weather Service. They are predicting showers for Wednesday and Thursday and, by Friday, chilly temperatures.