Searing Heat Wave Drives Record Temperatures Across Eastern U.S.

Rebecca Falconer

Man carries a case of water as people try to stay cool in Newark, New Jersey as residents of New Jersey and much of the Northeast experience the season's first heat wave where temperatures are expected to reach into the high 90's with a heat index of over 100 degrees on June 19.

An intensifying heat wave that's striking the Midwest to the Northeast has seen multiple new maximum temperature records set or tied this week.

The big picture: Officials in several states have activated emergency operations and opened cooling centers in response to the lingering heat dome that left over 91 million people under heat alerts Thursday morning.

State of play: New York Gov. Kathy Hochul has activated emergency operations that are in effect through Friday for parts of the state impacted by the heat dome and Boston Mayor Michelle Wu declared a heat emergency that's effective through Thursday.

Connecticut Gov. Ned Lamont's extreme hot weather protocol will remain in effect through 12 noon Sunday.

By the numbers: Southern New England saw multiple new daily temperature records set, including in Boston, which hit 98°F on Wednesday.

The National Weather Service noted on Wednesday several Maine cities were tied for the hottest June 19. This included in Caribou, which reached 96°F and preliminary data indicated the 103°F heat index an "unofficial all-time record."

Hartford, Connecticut, hit an all-time daily high of 97°F, while in New York both Syracuse (95°F) and Albany (94°F) tied their calendar-day records.

Threat level: The National Weather Service warns that the heat dome that will have edges from the mid-Atlantic into the mid-South over the next couple of days, is set to produce more record-breaking heat across the Great Lakes, Northeast and mid-Atlantic.

"Afternoon high temperatures and warm overnight lows will challenge daily records and even some monthly and all-time records," it said in a Wednesday forecast discussion that urged those without access to reliable air conditioning to find a way to cool down.

Heat index readings are expected to peak from 100°F to 105°F in many locations.

"Record warm overnight temperatures will prevent natural cooling and allow the heat danger to build over time indoors without air conditioning."

Between the lines: Studies show that economic productivity takes a hit during extreme heat events, and that climate change is likely to worsen these impacts in the future, per Axios' Andrew Freedman.

Global warming is making heat waves more likely, more intense and longer lasting and research has found that some heat waves would have been "virtually impossible without human-caused climate change."

What's next: Conditions should improve over New England by Friday due to a cold front, but the NWS warned that temperatures well into the 90s°F and higher heat indices were forecast to continue across the Ohio Valley to mid-Atlantic.