At what should be the loveleafest time of the year -- trees yellow and red and orange, woolly sweaters, brisk walks -- there sat the lap swimmers, sunning by the pool.
Just last week, when the mercury was at 37 degrees and steam made the pool appear primeval, lifeguard Dave Zahern waited at water's edge with warm towels for the diehard swimmers. Yesterday, it was brilliant sun, coconut oil, lounge chairs and lazy laps.
"Oh, loving it. This is just the best," said Carla Merriman, fresh from the water and dripping wet in her yellow bikini. "We all feel like kids in a candy store, and it's so beautiful and clear."
And hot, at least for November's first week, when chilly winds normally bring out the hot apple cider and hot chocolate.
Yesterday, the District fell just shy of the 80-degree record set in 1974, reaching a high of 79 at National Airport at 1 p.m.
But it was record-breaking in Baltimore, where the 82 degrees reached in downtown at 1:20 p.m. passed the 1975 record by two.
At Baltimore-Washington International Airport, the National Weather Service reported a high of 78 degrees at 2:15 p.m., breaking the record of 77, also set in 1975.
And at Dulles International Airport, the high of 81 degrees at 1:58 p.m. tied the record set in 1982. Forecasters predicted a similar day today, with temperatures again nearing 80.
The swimmers belong to the Spa at the Washington Hilton Hotel in Northwest, which extended its outdoor heated-pool schedule through the weekend, well past the Oct. 31 closing date, because of the warm spell.
Throughout the region, sunny skies drew thousands to parks, bike trails and marinas, at times taxing services that suddenly were handling summer-like crowds.
At Alexandria's Washington Sailing Marina, Pam Peters couldn't keep up with the requests.
She was out of rental bikes by 11 a.m., and all day she told disappointed customers that boat rentals ended Oct. 31.
And those who had prepared their boats for winter lamented being land bound.
"Today would have been an awesome day to cruise down river," said Danny Dunphy, 17.
The unseasonable temperatures, forecasters said, were caused by a high pressure system centered over North Carolina.
The same system challenged records from Texas to North Dakota several days ago, and as it moved eastward it brought temperatures in the 70s and 80s to areas from New England to the Gulf.
More seasonable weather is expected to return tomorrow, when a storm out West will cut through the Great Lakes.
For the region, that should mean rain tomorrow and Tuesday, said Wayne Albright, a forecaster with Accu-Weather.
In some cases, the weather was somewhat disarming, especially for those attending events more appropriate to the season.
At Howard University's Greene Stadium, where the Bison took on the Bears from Morgan State University, they were hawking fruit juice in the stands.
"This is a little hot for football," said Catrice Mays, a junior at Howard who was buying a Frooty Patooty ice cream. "It is crazy."
And then there was the 3rd Annual Washington Ski Show and Winter Carnival in Ballston Common shopping center in Arlington, where merchants peddled fur hats and long underwear, and tried to get people to think snow.
"My boss told me to bring a book because he thought business would be slow," said Natalie Hocknell, a sales consultant for Ski Ventures, a Rockville travel agency.
At Great Falls National Park in Virginia there were so many picnickers that a parking spot was hard to find by 11 a.m. Wasima Ebrahimi wasn't about to let a day like that go by, so she called her sister and brother-in-law, loaded the car with charcoal, hamburger patties and salads, and headed for the park.
"It's a no-sweater and no-jacket day in November," she said.
Those who had to work found themselves shedding clothing. Security guards at the Howard game didn't know what to do with their jackets. In Hyattsville, postal worker Nick Shuck beat the heat by wearing his summer uniform.
"This is the first time I've been able to wear shorts in November," said Shuck, who has worked in Hyattsville for five years.
On the Mall, where hundreds turned out, there were bikers and babies, footballs and Frisbees, joggers, walkers and just plain sitters. Georgetown University students Coleen Hennessey, Alison Chmiel and Kristin Franciszkowicz packed up their English and government books and rode the bus to the Mall.
"There's no point staying home on a day like today," said Hennessey. "This kind of weather isn't going to last for long."
Just down the Mall, D.C. artist Roderick Turner was standing at his easel to capture the scene in watercolors. Dabbing at his painting of the Mall, showing the Smithsonian Castle silhouetted against the sky, Turner said the angle of the light was particularly good for the kind of painting he likes. In summer, the light is sometimes too strong, and in winter it can be too pale, he said. Fall is his favorite, and yesterday it was perfect.
"It's not every day you get this kind of weather," he said. Staff writers Retha Hill, Mary Jordan and Molly Sinclair contributed to this report.