Driven by a merciless sun blazing in a near cloudless sky and by a hot wind, which eddied up from the burning pavements, the official thermometer in Washington rampaged upward yesterday to a new all-time heat record.

Neither heat nor hyperbole is new to this town.

The heat that drove a scribe in 1930 to write the top of the news article you just read may repeat itself Saturday. Only cool-headed editors will determine whether the same sort of overheated prose reappears, too.

The temperature that caused the official thermometer to rampage that day — July 20 — was reported to have reached 105.6 degrees. History has rounded that up to 106, tying the 1930 date with another in 1918 for the hottest day ever recorded in Washington.

The heat wave that began more than a week ago already has set several records, including hottest day ever in June (104 degrees) and longest stretch of days over 95 degrees (nine and counting).

Saturday may be the wave’s apex, but will it match 106?

“We’re expecting maximum heat of 100 to 105 degrees, with the heat index values at 110,” said Heather Sheffield at the National Weather Service office in Sterling.

She said Sunday would be much the same, with temperatures in the high 90s, before a cold front blows in, bringing the possibility of large hail and wind gusts up to 60 miles an hour.

Power knocked out by a freak storm a week earlier had been returned to most people in the region by late Friday. There were 8,725 customers still without electricity, almost half of them in Montgomery County, far below the peak of more than 700,000.

Noting the expected extreme heat, as well as the high demand and the damage to the system, Pepco asked customers to conserve electricity.

But about 4,300 Dominion Power customers in Herndon suddenly lost power Friday evening.

Utility crews from all over the country were wrapping up work and soon would head home.

“I’d love to see the White House when we’re this close,” said Jesse Ellis, 24, of Toronto’s Hydro One utility company. “A drive-by, even.”

The number of people fatally stricken by heat-related issues continued to rise, with Virginia officials saying there had been 10, including five in the state’s northern health district. The District Department of Parks and Recreation canceled all outdoor events and will close all fields Saturday because of the expected record-breaking high temperatures.

For some, the heat has brought a business boom. Local hardware stores say popular items include battery-powered fans (ideal for those daytime power outages) and cheap coolers (insert ice and chill).

“We’ve actually been the busiest we’ve been in a long time,” said Brian Stauber, assistant manager at Logan Hardware on 14th and P streets, part of a seven-store chain. “It hasn’t stopped since the storm came through.”

First it was the battery-powered lanterns and flashlights, he said. Now, nearly a week after the derecho roared through the region, it’s air conditioners and fans of all types that are selling quickly.

“It’s almost impossible to keep the shelves stocked,” he said.

There was neither a heat index nor air conditioning when Washington first tasted 106 degrees on Aug. 6, 1918. The temperature was reported to have hit 121 degrees at the D.C. courthouse. A shortage of ice caused tons of food to spoil in open markets and stores. From Winchester, a farmer reported that 120-degree temperatures were baking apples on the trees in his orchard.

When the thermometer rampaged back up to the record in 1930, people and birds alike sought out water. More than 5,000 bathers turned out at Chevy Chase Lake.

At Washington National Cathedral, Canon G. Friedland Peter read a prayer for rain from the new Episcopal prayer book. It was believed to be the first invocation of that plea from the new book.

Air conditioning had been invented but was rare.

President Herbert Hoover and the first lady, Lou, reportedly stationed themselves under a ceiling fan in the White House until late in the day, when they took a drive in Rock Creek Park.

An editorialist advised:

“There is nothing the public can do about [the heat] except rush to the water front or swimming pool, seek out shady places, demand inordinate amounts of ice cream and cold drinks, and — talk about the weather.”

Nikita Stewart, Lena H. Sun , Clarence Williams and Susan Svrluga contributed to this report.