After a few brief days in which August had begun to soften its surly image, summer once again blasted the Washington area yesterday, posting a near-record temperature of 95 degrees accompanied by humidity that made the capital a hothouse.

The day's high was just two degrees short of a record set for the date in 1968, and cut ruthlessly short a respite from the record-setting string of 90-degree days last month.

But fear not. The National Weather Service predicts things will begin to cool down again tonight, with another interval of cooler and less muggy weather in store for much of the week. Temperatures this week are expected to range from the mid-80s to around 90 degrees.

"It's going to be pleasant weather, real pleasant weather," said Weather Service specialist Joe Cefaratti. "Of course, it will be a lot less humid."

Four Virginia counties -- Buckingham, Goochland, Powhatan and Southampton -- have asked to be designated drought disaster areas because of the extended dryness.

In parts of Maryland, lack of rain has seriously depleted water reservoirs. Frostburg in the western part of the state imposed water rationing yesterday for the second time since 1983. City officials there are hoping to avoid an even worse shortage of water next month, which is normally drier.

In the Washington area, periodic, scattered thunderstorms are predicted for the rest of the week, then a possible return to roller coaster heat and humidity is foreseen.

"There may be another repetition of it coming up," said Cefaratti. He explained the cycle, saying the high-pressure systems that pass through here -- bringing first cooler air -- tend to lose steam and linger off the coast, pumping in hot and humid air. "They just don't have the energy to go all the way through" to make way for another cool system, he said.

Heavy use of electricity caused by the heat prompted 11 mid-Atlantic utilities, including the Potomac Electric Power Co., to reduce voltage 5 percent from 1:26 to 6:02 p.m.

A Pepco spokeswoman said the reduction "should have had very little adverse impact on most computers, motorized equipment and appliances."