Bright sunshine and springlike temperatures blanketed much of the mid-Atlantic region yesterday, setting a record at Dulles International Airport while creating an unseasonable bustle of outdoor activity on campuses and in parks.

Under the influence of the jet stream and a high-pressure system more characteristic of July than November, warm air spread across the nation's middle latitudes from Annapolis to Kansas City, toppling or tying records in two dozen cities.

National Airport, where Washington's official readings are taken, was a cool spot yesterday, with a high of 68, because of a breeze coming off the Potomac River, experts said. Warmer temperatures, possibly reaching the upper seventies, are expected today.

At Dulles, yesterday's high reading of 75 eclipsed the 73 degree record for the date set in 1973. Records also were set in Roanoke (74) and Richmond( 75.) Highs in the seventies also were reported in Cumberland and Hagerstown, Md., and in Charlottesville.

"Normally in November the {American University} campus would look empty from the outside," said senior Lori Goldman. But yesterday, she said, there were "lots of people hanging out . . . between classes," carrying their jackets, but not wearing them.

"Our golf courses are unusually busy for this time of year," said Darrell G. Winslow, executive director of the Northern Virginia Regional Park Authority.

He said boaters, hikers and bicyclists were out in force on Sunday in particular, a day on which the official temperature reached 73 degrees, 19 above normal. "Generally, people are out just like summertime," Winslow said.

Temperatures have remained above normal since Wednesday, giving no hint that the start of winter is little more than three weeks away. The unusual weather is expected to continue until a cold front arrives Thursday, forecasters said.