By Alex Sosnowski, Expert Senior Meteorologist
Jun 8, 2011; 5:50 AM ET
Heat that has been building in the mid-South in recent weeks will bake the East today into Thursday.
Intense June sunshine combined with building humidity and hot air will push AccuWeather RealFeel® temperatures to dangerous levels during the heat wave.
Caution is always advised during hot, sunny days. However, extreme caution is urged today and Thursday.
The heat will be hard on the very young, elderly and those who must work outdoors.
While the heat will be nasty enough throughout the region, the large cities will have the worst of it as usual.
Just as urban areas begin to cool down to reasonable levels during the early morning hours, the sun will already be rising on the next day, preparing to broil the landscape all over again.
From near the Mason-Dixon Line on south Thursday, the 100-degree mark could be challenged on I-95 city thermometers from Philadelphia and Wilmington, Del., to Baltimore, Washington, D.C., and Richmond.
This heat wave has already been responsible for sending triple-digit heat into the nation's northern tier. The high in Minneapolis hit 103 degrees on Tuesday, shattering record high of 95 degrees from 2004. Not only was the record high shattered, this was the hottest temperature recorded in the Twin Cities since the thermometer hit 105 degrees on July 31, 1988.
Although not the first heat wave of the season for the southern mid-Atlantic, it will probably bring the hottest weather so far this year for much of the East.
Record highs set more than 75 years ago will be challenged during the heat wave, including in the major I-95 cities.
The hottest it has been in Boston so far was 87 degrees; New York City reached 90 degrees and Washington, D.C. climbed to 98 degrees. All three cities and many others could eclipse this mark during the upcoming two days.
The heat will ease across the Northeast on Friday, but not before a new round of potentially damaging thunderstorms on Thursday.
Heading to the beach or the public pool is one way to beat the heat if you don't have air conditioning.
While ocean water temperatures are still traditionally chilly during this part of the season, the surf is running several degrees above normal levels for early June.
For example, at Atlantic City, N.J., the water temperature was 69 degrees Tuesday afternoon. Typical water temperatures for early June are 62 degrees.
There are a few exceptions, where local upwelling or cold eddies are present.
Remember to take frequent breaks from the chilly water to avoid muscle cramps and reduce the risk of drowning.
Only swim in lifeguard-protected beaches.
Be sure to keep a close eye on young children at all times.
Never leave children unattended in parked vehicles for any length of time. Heat can build to lethal levels in only a few minutes.