BETHLEHEM, Pa. — No climate site in the region reached 100 degrees on Monday, but the suffocating heat and humidity still was record-setting.
The National Weather Service said seven of nine climate stations across the Mid-Atlantic tied or broke record highs:
Allentown: 97 degrees (new record)
Atlantic City Airport: 98 degrees (new record)
Atlantic City Marina: 93 degrees (new record)
Georgetown: 99 degrees (tied record)
Mount Pocono: 93 degrees (new record)
Philadelphia: 99 degrees (new record)
Reading: 99 degrees (new record)
Trenton: 97 degrees (new record)
Wilmington: 99 degrees (tied record)
Mount Pocono reached 90 degrees about 2 p.m., marking the first 90-degree temperature there in 13 years, when the high was 90 on July 19, 2013. The daily record for Monday was 90 degrees, set in 1908.
Monday’s temperature in Mount Pocono also set an all-time June record, the weather service said. The previous all-time June record was 92 degrees, set on June 24, 1914; June 9, 1933 and June 26, 1952.
Mount Pocono topped out at 93° today, setting an all time June record. The previous all-time June record was 92°, set on 6/24/1914, 6/9/1933, and 6/26/1952. #PAwx https://t.co/sqeYR6iZqB
— NWS Mount Holly (@NWS_MountHolly) June 24, 2025
Overnight records also fall
Even after midnight, many locations across the region still had heat index values in the upper 80s and 90s. The lingering heat and humidity also helped to obliterate more records under the cover of darkness.
The weather service said all climate sites except Reading set record warmest low temperatures for June 23.
The overnight temperature at Lehigh Valley International Airport was 73, beating the previous record warmest low temperature by two degrees.
Early Tuesday around 3:35 a.m., it was 81 degrees and felt like 85 in the Allentown area.
Dangerous heat continues
Forecasters say the heat wave will continue in full force through Wednesday, with temperatures in the mid-90s to near 100 and heat indices of 100 to 110 across the region.
“An extreme heat warning will remain in effect for all but Carbon and Monroe counties, and a heat advisory for Carbon and Monroe, through 8 p.m. Wednesday,” the latest NWS forecast discussion said.
“With the ridge beginning to break down and a cold front approaching from the north, a few showers and storms will be possible beginning Wednesday afternoon and into Wednesday night.
“With strong surface heating enhancing low-level instability, gusty winds could occur with any stronger storms,” the discussion said.
Storm chances will repeat on Thursday as a cold front finally crosses the region.
