Overnight thunderstorms peppered the Northeast on Monday and threatened to return with damaging wind gusts and hail.
Gusts up to 70 miles per hour and large hail were forecast through Monday evening in parts of Connecticut, Massachusetts, New Hampshire, New York and Rhode Island, the National Weather Service said.
The system was heading northeast after moving through parts of Iowa, Minnesota, Wisconsin, Ohio and West Virginia.
Heavy rain fell across the Minneapolis-St. Paul metro area, flooding some lanes on Interstate 94, knocking down trees and cutting power to about 25,000 Xcel Energy customers.
The National Weather Service said it received reports of half-foot thick tree branches down in Minneapolis, whose western suburbs saw over an inch of rain fall in minutes before the storm plowed across the region.
South of the Twin Cities, the weather service received reports of dime-sized hail and heavy winds.
Kevin Roth, lead meteorologist at The Weather Channel, wrote that severe thunderstorms could strike from central Pennsylvania through New England. "Damaging wind gusts, hail and a few tornadoes are possible with those storms," he said.
He also said temperatures could top 100 degrees in parts of Virginia.
Farther south, in the Central and Southern Plains, no relief was in sight.
Areas of Kansas, Missouri and Oklahoma were under excessive heat warnings with heat advisories issued for a large swath of the central United States, according to the National Weather Service.
Looking back at the sweaty month of July, NWS meteorologists said records were set for the hottest month ever in Oklahoma City; Washington, D.C.; and Wichita Falls, Texas.
Bobby Boyd, a meteorologist with the NWS in Nashville, said that July was the hottest in nearly two decades, with the 27 days reaching 90 degrees Fahrenheit and above.
"Nashville had what may very well be the highest heat index on record," Boyd said, when the high temperature combined with high humidity to produce a heat index of 114 during the afternoon of July 11.
Forecasts called for Monday to yet again reach up to the mid-90s, stretching for 100 in the next few days, according to Boyd. NWS issued an excessive heat warning for the western part of Tennessee, with expectations for Memphis to hit 100.
Heavy pollen in parts of the state will add to air quality issues exacerbated by the unrelenting heat.
Further south the NWS extended a heat advisory for New Orleans to the end of the week, anticipating a heat index of 113 Tuesday through Thursday.
Coast to coast, 2,676 high temperature records were smashed or tied in July, said forecaster Mary Yoon on Accuweather.com.
"The hot streak is likely to continue in August, as another heat wave is underway once again," Yoon said.
The unrelenting heat in central and eastern states has led to a slew of "Heat Superlatives" in 2011, according to Weather Channel meteorologist Chris Dolce.
More than a dozen U.S. cities from Tallahassee to Minneapolis have seen all-time highs exceeding any temperature on record for any month, Dolce reported Sunday.
High heat put Reading, Pa., on the map for 106 degrees Fahrenheit — its hottest day since at least 1869 — and Childress in thirsty Texas hit the highest mark at 117, a temperature not seen since 1893.
'Pretty incredible'
Heat and humidity were forecast to continue with air temperatures and heat index readings climbing well into the triple digits for parts of the central United States at least through midweek.
"It's pretty incredible to just be locked into a pattern of this kind of dry heat for this long for the Southern Plains," said AccuWeather.com senior meteorologist Dan Pydynowski.
"There doesn't seem to be any relief in sight," he said.
For farmers like Bryan Burgess in Ashville, Ala., this lack of relief from continued heat means more bad news for business.
Burgess said he has had to fire employees for fighting over air-conditioned tractors and trucks, which are slower and more prone to overheating.
"Heat brings out the worst," Burgess said. "Some folks think that the upper 90s should not drive away or create problems for help. But, when you take a load of hay to put into a barn loft, the heat in the loft is 140 degrees. Do you know anyone who would do this type work?"
Burgess' wife Leslie said her horses are drinking so much more than usual that she is seeing the difference in her water bill.
Even in places where high heat is typical for this time of year, the prolonged top temperatures are extreme.
Tennessee had heat indexes of over 100 Sunday, with triple-digit real temperatures to follow by midweek.
Dallas has reached or topped 100 degrees for nearly all of July.
"Yes, they are used to the heat, but to have this many days in a row of triple digit heat is extreme even for a hot place like Dallas," Pydynowski said.
The unrelenting stretch of hot, dry weather in Texas has sent an increasing number of people to emergency rooms for heat illness.