The intense heat wave that has broken thousands of records from the Plains to the Eastern Seaboard will begin to lose its grip on the weather, but not after peaking for millions today.
Temperatures will soar well into the 90s and even past 100 in some big cities from near New York to Raleigh and Charlotte to start the weekend.
Philadelphia, Baltimore and Washington, D.C., are all expected to rise into the low 100s, tying or breaking records.
"Saturday could potentially be the hottest day of the summer for Philadelphia, Washington, D.C., and other cities of the Northeast," AccuWeather.com Expert Senior Meteorologist Alex Sosnowski said.
Of course, the thermometer reading, while impressive, won't do justice to how it truly feels.
The combination of the heat with intense sunshine and high humidity levels will yield AccuWeather.com RealFeel® temperatures as high as 115 in major metropolitan areas during the peak heating of the day, between noon and shortly after sunset.
RealFeel® values this high are at dangerous levels for not only the old and infirm, but everyone who spends a prolonged amount of time outdoors. Hydration and frequent respites in air conditioning will be key to weathering the brutal heat.
Even folks seeking refuge at beach locales will have to endure the searing temperatures thanks to an offshore flow that will only cede to a sea breeze in some areas late in the day.
While the heat will peak in the big cities along I-95 today, record temperatures near or above 100 that other major cities such as St. Louis, Chicago and Cincinnati have become accustomed to will persist yet another day.
However, a cold front which has already erased the triple-digit heat from the Upper Midwest will further squash it to the south over the next few days.
Temperatures above 100 in Philadelphia and D.C. will be replaced with 90s on Sunday and then more seasonable 80s for the rest of next week. Accompanying the cooldown will be a reduction in humidity levels, making a world of difference to how it feels to be outdoors.
The transition will not be smooth, however, with severe thunderstorms expected to rock a portion of the Great Lakes, mid-Atlantic and Northeast.
The late-season swelter will continue along much of the Atlantic Seaboard through the week as tens of millions head back to school and work.
The next Atlantic tropical depression or storm may take shape in the southwestern Gulf of Mexico's Bay of Campeche during the next couple of days.
A second volcanic eruption occurred on Sunday morning in Iceland in the same area that had one on Friday.
Severe thunderstorms will threaten holiday festivities across parts of the Midwest to close out the extended Labor Day weekend.
While flooding is a threat, monsoonal rains will be beneficial for most areas across northwest India this week.
Gusty winds, large hail and power outages occurred Sunday into Monday morning in the north-central United States.
Yuma, AZ (1950)
123 degrees - hottest temperature ever in Yuma. Yuma is the hottest city in the U.S.
Los Angeles, CA (1955)
110 degrees, hottest day ever in September. This mark was tied September 4, 1988.
Milwaukee, WI (1988)
Hottest summer on record. Six days of 100 degrees or greater and 36 days of 90 or above. Average temperature of 73.8 beat the old record of 72.8 set in 1921 and 1955. The normal average tempera- ture for a summer in Milwaukee is 68.3 degrees.