Washington temperature climbed into the steamy 90s once again yesterday, continuing a trend that forecasters say could make this July the hottest in the city's recorded weather history.

It was hot at National Airport, Washington's official measuring station, where a high of 92 degrees was recorded, and where there was no trace of the localized showers that brought brief relief to parts of the metropolitan area.

It was also hot at the Small Business Administration headquarters at 1441 L St. NW, where employees were allowed to leave after the air conditioning failed.

"It was a furnace," said Anthony Stasio, an SBA spokesman.

And it was hot not only in Washington, but elsewhere around the nation and the Maryland and Virginia area. Richmond recorded 101 degrees, which was topped by the 102 in Roanoke.

For Washingtonians, the discomforts of heat and humidity were exacerbated by air pollution levels in the "very unhealthy" range.

Although yesterday's pollution reading of 105 was down from the readings of the previous three days, it was still above the "very unhealthy" threshold of 100. The area's fourth air pollution alert of the year was extended for at least another day.

Authorities offered no prospect of any relief from the monotonously oppressive heat.

"Nothing can be done about it," said George P. Cressman, director of the National Weather Service.

"All you can do is seek out air conditioning or some cool place." Cressman said in a brief interview.

As have other forecasters, the Weather Service chief pointed out that the large scale flows of cool air that traditionally sweep south to moderate Washington summers have not reached here this month.

"The main atmospheric circulation is taking place farther north," he said.

While prospects for a change in the weather pattern in the next two weeks look poor, said forecaster Chet Henricksen, the chances that this July will become the city's hottest ever "look good."

The hottest July recorded came in 1955, when the average temperature, a figure based on the daily highs and lows, was 82.1 degrees.

Readings so far this month have been running about one degree above the 1955 figures. Henricksen said. The average of yesterday's high - 92 - and low - 75 - was 83.5.

For those area residents who may be wondering if it might be unusual to have so hot a summer follow so cold a winter. Henricksen made reference to the year 1966.

Not only was there a cold winter in 1966, he said, but from April through September of that year, the temperature set a record by reaching 90 degrees or above on 58 days.

So far this year there have been 25 such days, 16 of them this month, including the last seven in a row.

For those inclinde toward the quantification of misery, the record for the number of successive days with temperatures of 90 or above is 18, set between June 27 and July 14, 1872.

The current hot spell began on June 26, with a high temperature of 91, according to the National Weather Service. Since then, there have been only two days on which the temperature failed to reach 90 degrees.

The highest temperature during the period was the 100-degree reading reached on July 6. The reading was six degrees below the all time record here of 106, recorded in 1918 and again in 1930.