The watch is in effect through 10 p.m. Tuesday, July 16 and applies to all of New Jersey.
In Pennsylvania, the watch covers Adams, Berks, Bucks, Carbon, Chester, Dauphin, Delaware, Lackawanna, Lancaster, Lebanon, Lehigh, Luzerne, Monroe, Montgomery, Northampton, Philadelphia, Pike, Schuylkill, Wayne, Wyoming, and York in Pennsylvania.
Temps are expected to feel as hot as 100 or 105 degrees in much of the region, according to the NWS.
A chance of showers and thunderstorms that could produce heavy rainfall is being forecast after 5 p.m.
Wednesday will be mostly sunny with a high of 96 and another chance of showers and thunderstorms after 2 p.m., according to the NWS.
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