It has brought greener lawns, more vegetables and less demand for electricity. It will mean soggier pumpkins and squash come fall, more ragweed and a bumper crop of mosquitoes.

The first 20 days of August have been wetter than normal, producing just under six inches of rain compared with the average 4.4 inches. And yesterday, to some, an August day came with a chill.

Where the eighth month normally is hazy and hot, with every third day baking in 90-degree or higher temperatures, this August has been damp and cool like a poorly insulated basement.

"It feels cooler, because it is cooler," said Kenneth W. Reeves, senior meteorologist for Accu-Weather, who noted there have been only three 90-degree or higher days this month, the last on Sunday. Yesterday, for example, the temperature fell to 68 at midnight -- one degree above the lowest high temperature ever recorded for the date in 1926 -- then decreased through the day. By midafternoon, the temperature hovered around 65 degrees, but 14 mile-an-hour winds made it feel much chillier.

The rain is one reason that the month has been cooler. "With more moisture in the air, it's more difficult for the temperatures to rise," Reeves said.

But also yesterday, the area was affected by a large high-pressure system in eastern Canada pushing cool air down the East Coast as far south as Virginia. Normally Washington's summer months are dominated by the Bermuda High, the mass of moist hot air that usually sits off the southeastern United States from June through August.

For area businesses that bank on Washington's muggy summer days, the cooler, wetter weather has meant off sales for some but barely a dent in customers for others.

At the Putt Putt Golf Course in Rockville, about 100 people played through a light drizzle at midday yesterday. "The rain hasn't affected us. We are having a very good month," said manager Robert W. Hummer.

But at Belle Haven Marina Inc. in Alexandria, one of the largest renters of sailboats and small fishing boats in the area, business in July and August has been off by 37 percent, owner George Stevens said.

"The die-hard fisherman will fish regardless of the weather, {but} the recreational boater, they want to come when it's sunnier," Stevens said.

But for farmers and utility companies, the weather has brought some relief.

At the beginning of the summer, the Potomac Electric Power Co. and other area utility companies warned of high demand and predicted periodic brownouts, or voluntary voltage reductions. But so far, Pepco has had to institute that emergency measure only once, on July 5 when the mercury hit 100. Virginia Power also reduced voltage output on that date to help Pepco when the utility's equipment failed, causing blackouts in some communities, a spokesman said.

Pepco spokeswoman Dana Grabiner also said the number of hours that customers use their air conditioners is down 5.2 percent.

"We haven't had a typical Washington summer," Grabiner said. "Even with a few days in the nineties, we've been able to meet demand without having to institute emergency procedures."

Farmers and consumers also can expect to enjoy a large crop of sweet corn, soybeans and tobacco this year because of the rainy weather. But fruit and vegetables such as cucumber, cantaloupe, pumpkin and squash might be plagued with mildew, said David L. Conrad, a University of Maryland Cooperative Extension Service agent.

And allergy sufferers should brace for a thriving crop of ragweed that is proliferating in the moist earth now and should be air bound by September.