Those who were up early yesterday experienced a brief brush of cold weather as temperatures plunged below 40 degrees in the Washington area, setting a record low for May 4.

The record was established at 6 a.m. when the temperature dipped to 39 degrees at National Airport, one degree below the previously recorded low set in 1957, according to the National Weather Service. The normal low for the date is 52 degrees.

Temperatures plummeted even further in the western suburbs, where a reading of 33 degrees was recorded at Dulles International Airport, although no record was broken. A low of 35 degrees was recorded at Baltimore-Washington International Airport.

All-time lows were recorded in Richmond and Roanoke, where temperatures dropped to the freezing mark overnight.

The 39 degrees recorded yesterday morning at National Airport was six degrees above Washington's all-time low for May, a record that was set on May 11, 1911, when the temperature dropped to 33 degrees.

Edward R. Schoenberg, a spokesman for the National Weather Service, attributed the brief cold spell to a frigid high-pressure system that moved eastward through West Virginia this weekend. The cold air pattern, which forced the temperatures down to the 40-degree mark on Saturday morning, overtook a warm air mass that kept the temperature above 60 degrees during most of last week.

Much of the East Coast felt the effects of the cold air system, as record lows were set in cities from Maine to South Carolina. Among those recording all-time lows were: Syracuse, N.Y., 27 degrees; Providence, R.I., 31 degrees, and Knoxville, Tenn., 32 degrees.

The East Coast's coldest spot was Elkins, W.Va., where the temperature dropped to 21 degrees.

The National Weather Service issued freeze warnings to area farmers early this weekend, but spokesmen said yesterday that it was too early to assess the impact of the cold weather on crops.

The good news, Schoenberg said, is that the cold air system will leave the area as quickly as it arrived. Temperatures were expected to get no colder than about 50 degrees last night and soar back up into the 80s today, tomorrow and Wednesday.

Even as the record low was set yesterday, by 11 a.m. the temperature had already crept back up into the mid-50s, and by midafternoon area residents were enjoying 70-degree weather.

According to Schoenberg, the abrupt temperature swings during the past three weeks are typical of Washington springs. He said that although the area is unlikely to experience such cold temperatures again as the summer approaches, anything can happen. Thus, his cautious forecast:

"There shouldn't be any more of these cold temperatures -- at least for the next several days," he said.