Out came the corduroy coats, flannel shirts and woolen skirts yesterday as the first full day of fall breezed into the Washington area, bursting with brilliant sunshine but cooled by gusting winds and below-normal temperatures in the 60s.

"It's more like the second or third week of October," said James Travers of the National Weather Service, as the day's temperatures rose from a low of 52 to a high of 68, about 10 degrees below normal. Save for cooler than normal temperatures, Travers said the classic fall offering-- blue skies, dry, invigorating air-- was fairly typical of the season.

Yesterday's alluring sunshine beckoned Washingtonians outdoors, only to have the wind steal the warmth from its inviting rays. Downtown merchants propped open their doors while sidewalk cafes, their days numbered for 1981, did steady though unspectacular business. And along the Mall, where flags snapped in the bracing wind, joggers loped past with dry sweatbands and tourists smart enough to visit Washington at this time of the year toured in happy ignorance of Washington weather in August.

Typical was the scene at Dupont Circle, where the park benches facing the sun filled up early with noontime brown baggers and philosophers determined to sit outside on such a glorious day.

Lauren Kramer, an office manager for Energy Action, a public interest firm, basked in the sun but huddled against the wind as she read "All Creatures Great and Small."

The crisp sunlight and cool temperatures provided perfect sleeping conditions for one Dupont Circle fixture. Cocooned in a soiled, Air Force-issue flight jacket, a panhandler dozed peacefully, his head resting on a thick volume entitled "The Age of Surveillance," subtitled "The Aim and Method of America's Political Intelligence System."

Forecaster Travers said the wind yesterday made the mid-60s temperatures feel much colder. "We can start talking about the wind-chill effect again," he said.

Travers said the long-range forecast for the rest of the year calls for more precipitation than normal. "Rainfall has been below normal this year. In general, we have been running pretty dry," he said.

One good thing, he said, the drier weather so far means this autumn's leaf colors should be spectacular.

"The dogwoods seem to be changing early, oaks are getting yellowish. We're looking for a good frost in the suburbs within the next couple of weeks," he said.

Yesterday should prove to be just a teaser of things to come, Travers said, because early-morning temperatures today were expected to dip into the 40s in the suburbs and low 50s in town.

But the unseasonably cool temperatures and winds that reached 27 mph yesterday should give way later today to a warmer air that is expected to push the mercury back into the mid to high 70s. That is the more normal temperature range for this time of year, he said.