In this summer of extreme heat, the death tolls from the last heat wave were being counted Wednesday. Heat might have caused or contributed to as many as 64 human deaths, the National Weather Service said, while ranchers in several states reported thousands of cattle were lost to heat and drought.
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Wednesday also brought reports of two new weather records: New York City used a record 1 trillion watt hours of electricity over the four-day heat wave last week, while the Dallas-Fort Worth area saw its warmest early morning on record.
The deaths were across 15 states in the central and southern U.S., and not all had been confirmed as heat-related by local coroners, the service said. Countless more were treated for heat issues.
Livestock has also been greatly affected by the heat wave. A poll of Iowa Cattlemen's Association members indicates as many as 4,000 head of cattle died in Iowa alone.
Thousands more cattle were likely killed in other states, the weather service said.
Dal Grooms, spokesperson for the Iowa Cattlemen's Association, said farmers are doing all they can to protect their animals, but cattle are especially vulnerable as they don't sweat and rely only on respiration.
"I've talked to producers who've been out there just constantly looking for things to do to protect those cattle," Grooms said. "When it gets to be hot and humid like this, it is just very difficult to stop all losses."
Some parts of Iowa last week had six or seven consecutive days with temperatures in the mid to upper 90s and heat indexes as high as 110 degrees. The state remained under a heat advisory Wednesday.
Portions of Oklahoma, Kansas, Missouri and Illinois also remained under excessive heat warnings on Wednesday.
"The high pressure system responsible for the recent heat wave will remain in place across the central U.S. through Thursday, then a brief reprieve is in store," the service statement said in a statement. "The long-range forecast has heat rebuilding into the Central and Southern U.S. by early next week."
In New York, utility provider Con Edison said electricity usage would have been even higher had customers not conserved.
How does 1 trillion watt hours compare? "It's about the amount of electricity Vermont uses in two months," Con Edison stated.
Electricity usage peaked at 4 p.m. last Friday at 13,189 megawatts, breaking the old record set on Aug. 2, 2006, by 48 megawatts.
Saturday also set a weekend day record of 11,533 megawatts, topping the previous one set on July 24, 2010.
In Dallas, the National Weather Service said the lowest temperature there early Tuesday was 86 degrees — a degree more than the earlier record first set in 1939 and tied just last Monday.
Dallas has also seen 25 straight days of triple-digit heat. Wednesday should make it 26, with the forecast at around 103.
It's the third longest triple-digit stretch in Dallas' history. But there's still a ways to go to break the record of 42 days.
As for relief from the heat, areas from northwest Michigan to eastern Nebraska could see cooler temps but also severe storms.
Kevin Roth, lead meteorologist at The Weather Channel, wrote on its website that the main threats carried by the storms would be "damaging wind gusts and hail," but he added that "a few tornadoes are possible in southern Wisconsin and northern Iowa."
He also said that rainfall of up to 4 inches was possible during the thunderstorms and this could cause some localized flooding.
Roth said that day-time high temperatures in Texas would hit 95 to 108 degrees Wednesday with a similar range in Oklahoma. Temperatures in other parts of the South would range from the upper 80s to upper 90s.
He also said a developing tropical storm in the northwest Caribbean was forecast to move west-northwest into the southern Gulf Wednesday.
Roth warned it could possibly strengthen into a tropical storm by the end of the week and "impacts from the system could be felt in Texas as early as Friday."
Reuters contributed to this report.