Millions from Detroit to Boston face hottest temperatures in years from dayslong life-threatening heat wave

Not only could this heat wave become life-threatening, but it could also be record-breaking. Dozens of record-high temperatures are in jeopardy of falling this week, and some areas could even see their all-time hottest temperature.

PHILADELPHIA – Tens of millions of people from the Ohio Valley to the Northeast are about to experience the first significant heat wave of the summer, and it has the potential to be not only record-breaking but also life-threatening.


The sweltering temperatures are the result of a massive ridge of high pressure that’s establishing itself over the eastern U.S., and temperatures are set to skyrocket into the 90s and approach the 100-degree mark in many cities. The humidity will make it feel even hotter, with feels-like temperatures soaring above 100 degrees.

And many of those cities haven’t seen heat like this in years.

The National Weather Service office in Mount Holly, New Jersey, was very blunt with its forecast – "It’s gonna be hot!"

The NWS said Philadelphia, Allentown and Reading in Pennsylvania are expected to see at least five consecutive days of 95 degrees or higher. That hasn’t happened in those respective cities since July 2022, August 1953 and July 2011.


Heat alerts expand east

This graphic shows the active heat alerts through Friday, June 21, 2024.
(FOX Weather)


With the heat dome setting up shop across the eastern U.S., tens of millions of people are now included in heat alerts that will likely remain in effect through the end of the week.

Heat Advisories stretch from areas of Iowa, Illinois and Missouri in the Midwest through the Great Lakes region and Ohio Valley and into the Northeast and New England.

And those Heat Advisories include several major cities like Cleveland, Pittsburgh and Boston.

New York City, at this point, has not been included in any heat alerts.

An Excessive Heat Warning has also been issued for areas of Indiana, including Fort Wayne, Ohio and southeastern Michigan, including Detroit and Flint.

Excessive Heat Watches are also in effect in the Northeast, including the Philadelphia area and most of New Jersey. Portions of Connecticut, including Hartford, and Massachusetts, including Springfield, Lawrence and Norwood, are also among the locations included in the Excessive Heat Watch.


Heat cranks up as week continues

Boston will see a dramatic jump in temperatures as the new workweek continues, with forecast highs in the mid-90s. In fact, the forecast high temperature on Thursday is a sweltering 95 degrees.

New York City will also feel the heat, but it doesn’t appear that it will be as extreme as other cities. The Big Apple is forecast to remain in the mid- to upper 80s until Friday, when the city will see a forecast high temperature of 93 degrees.

Washington is also expected to stay at or above 90 degrees all week as the heat dome parks itself over the region.

Dozens of record-high temperatures could fall

This graphic shows the potential records that could fall on Thursday, June 20, 2024.
(FOX Weather)


Not only could this heat wave become life-threatening, but it could also be record-breaking.

Dozens of record-high temperatures are in jeopardy of falling this week, and some areas could even see their all-time hottest temperature.

With temperatures soaring into the upper 90s across the region, records could be broken in cities like Boston, Pittsburgh, Manchester in New Hampshire and Hartford in Connecticut.

Connecticut Gov. Ned Lamont took to X, formerly Twitter, to say the state’s Extreme Hot Weather Protocol will go into effect on Tuesday.

In the post, Lamont said he was working with local leaders to open cooling centers for people to beat the heat and stay safe.


Heat to reach life-threatening levels

In many of the areas where daily records could be broken or there is a lot of pavement, the National Weather Service’s HeatRisk map has labeled communities at a Level 3 or 4 out of 4 for impacts.

The HeatRisk threat level takes into consideration the unusual nature of the heat, the duration of the extreme temperatures and potential health impacts.

At a code red (Level 3) stage, heat affects anyone who is not adequately hydrated or those without access to cooling.

Magenta (Level 4) signifies extreme heat that is either rare or long in duration. Health systems can be impacted by an influx of patients with heat-related illnesses.


HeatRisk Map for Thursday.
(FOX Weather)


During the height of the heat wave on Thursday, most residents in Ohio, Indiana, New York, Vermont, New Hampshire and Maine will find themselves at a Level 4 out of 4.

The Centers for Disease Control and Prevention reports that the most common illnesses from warm temperatures are heat exhaustion and heatstroke.

Health experts warn that heatstroke occurs when the body’s internal temperature rises rapidly, overwhelming its ability to cool down. Heatstroke can result in serious health complications and is most prevalent among young children and older adults.