106 Chattanooga set a daily record high, breaking a 1936 record of 102 and tying an all-time high set July 28, 1952.
109 Nashville set a new all-time high, breaking a record of 107 on July 27-28, 1952.
102 Knoxville broke a 1936 record of 101 and tied its hottest June temp, set June 18, 1944.
103 Memphis broke a daily record of 101 set in 1988.
While it's blazing hot outside, the temperature is cool in TVA's systems operation center as a room full of weather and power technicians work to match the utility's electric output to demand in this record June heat wave.
But cool is relative on a record-breaking energy consumption day like Friday when the "average system temperature" for Chattanooga, Nashville, Knoxville, Huntsville and Memphis was 104.
As the mercury rose, so did the hum of air conditioners, and power demand in the Tennessee Valley neared its all-time record. It was a pressure day for the operators of the nation's largest public utility. And they knew it.
Friday's demand of 31,099 megawatts for 8.7 million residents was just shy of a 33,482 megawatt record set in Aug. 16, 2007 -- before the economic downturn.
"For every degree the temperature rises, we generally need to produce another 350 to 400 megawatts of power," said Scott Walker, senior program manager for operations in the Tennessee Valley Authority's "nerve center."
The Tennessee Valley was ground zero Friday for the heat wave that is making its way over the country.
The Scenic City set a daily record high of 106, breaking a 1936 record of 102 and tying a Chattanooga all-time high set July 28, 1952.
Nashville, though, led the state for hot: 109, setting a new all-time high there.
Sam Roberts, a meteorologist with the National Weather Service in Morristown, Tenn., said the weekend and Monday look like much of the same -- 103 or 104 over the weekend and about 100 on Monday.
"There's a slight chance on each of those days that maybe somebody will get a pop-up thunderstorm and get a little bit of rain out of it," Roberts said.
Roger Williams, owner of Mountain Service on Signal Mountain, said he has been busy with customers needing air conditioning repairs and tune-ups for a week.
He expects to be working 12- and 14-hour days this weekend and next week, when temperatures are expected to remain in the 90s.
"A lot of people have been trying to prepare for it, but we just can't get to everybody, and now the distributors are starting to run out of parts," Williams said.
North Georgia was no cooler, and like most East Tennessee counties, much of Georgia is under a heat advisory. The heat index is forecast to be between 109 and 111.
Mike Burns, who with his wife runs Burns Best Farm in Catoosa County, Ga., said even people accustomed to being outside have to be careful in this kind of heat.
"It's brutal. If you're going to be out today, you better have been up early. We might go out in the garden again a little after sundown," he said.
Burns said farmers have to make sure their livestock have plenty of water and are in the shade.
"Things just melt in the heat like this. And you've got to have irrigation," he said.
Rome's mercury hit 105; Dalton registered 100. Chickamauga reached 105, and Cohutta recorded 106, according to Robert Garcia, meteorologist with the National Weather Service in Peachtree City, Ga.
Mark Williams, spokesman for Georgia Power, said he could not provide Georgia Power's peak load information for several more days.
At TVA's operations center, occasional lights blinked on the circular wall that serves as a roadmap for the seven-state grid.
Operators opened and closed relays to troubleshoot alert lights, reroute power and read digital screens to maintain the all-important balance between power coming in and power going out.
"There are 100,000 data points that flow into here every two seconds," Walker said. "We know in real time what the power plants are generating and what the lines are handling."
When storms or other troubles cause stutters, Sheryl Roman, the "balance authority," has to decide whether to ramp up or dial down a plant. On Friday, she spent 12 hours gradually "walking up" power plant production.
"On days like this, you do have pressure. But it's rewarding. We're the ones keeping the air conditioners on, and the lights on," she said.
Her supervisor, Phillip Wiginton, manager of the balancing authority, smiled.
"I tell people it's like doing PlayStation 12 hours at a time without a reset button," he said.
Contact staff writer Pam Sohn at psohn@timesfree press.com or 423-757-6346.