Washington is suffering through a heat wave, but it's "just a little one," according to the folks who keep track of such things, and hardly the blistering record-breaker some might imagine.

"For July, as far as records go, it's kind of on the cold side," Calvin Meadows, a meteorological technician with the National Weather Service, said yesterday. "It's hot out there, but it feels hotter than it really is."

Sweat-soaked natives and panting tourists may have thought they were weathering the worst of times yesterday, especially since the mercury was already up to 83 degrees by 8 a.m. But these are the facts:

The high temperature yesterday was 97. The record temperature for July 8 is 98. The record high temperature for July in general is 106 degrees, a brow-wiper set July 20, 1930.

"It's just a little heat wave," said Meadows, noting that July temperatures so far this year have run "slightly above" the normal maximum temperature for July of about 88 degrees.

Those reports constitute the official insider's view. The following reports come from the streets.

"I almost fainted," said Jim Harden, 23, a Houston resident in town for a little sightseeing. He and a friend, Rich Gotwald, 27, were waiting on the Ellipse to watch President Reagan land in his helicopter, "but we had to leave because it was too hot in the sun."

Gotwald said he arrived expecting temperatures around 80 degrees.

Jane Jarvis, visiting the city for the first time from Miami, found the heat and humidity painful. "{It} makes my head hurt," she said.

The humidity made all the difference in how people experienced the weather, according to Meadows. The relative humidity of 45 to 50 percent yesterday was not excessively high by Washington standards, he said, but coupled with the heat, "it actually feels like 104 degrees."

Virginia Power's 1.6 million customers must have agreed. The giant utility company reported yesterday that it had what appeared to be an all-time record demand for electricity. Preliminary figures indicated that power use surpassed the record 10.64 million kilowatts consumed on Jan. 28.

Yet while some went to great lengths and expense to stay cool, others seemed to get a perverse pleasure out of mocking the elements.

Jill Dusenberry, for example, bought popcorn.

"It is pretty crazy, and here I am sweating, but it's either this or candy," said the 23-year-old Alexandria resident -- who quit smoking yesterday.

Some vendors said business was not affected by the weather; others said the heat was hurting sales.

"Last year, business was very good after the Fourth of July," said Hop Luong, operating her food cart on the Mall. "But business is slow now -- all they buy is soda and ice cream."

Trevis Markle of the Metropolitan Washington Council of Governments said the combination of hot sun, stagnant winds and automobile emissions had caused the area to exceed federal air quality standards several times so far this summer "and we're just barely getting into it."

There's been no need for a health advisory for several years, Markle said. Still, he advised, people with heart ailments or breathing problems should reduce their level of physical activity, and those in good health should be alert to symptoms of respiratory distress.

A spokesman for the Interstate Commission on the Potomac River Basin said water levels are below normal but there is no danger to the water supply. There hasn't been a critical water shortage here since 1966, he said, and the area is getting more precipitation this summer than last.