The most oppressive heat wave of the meteorological summer affected Eastern Pennsylvania from June 7th through the 10th. There were about twenty heat related deaths, eighteen within Philadelphia. There were also a couple of drownings within rivers. The combination of high temperatures well into the 90s and dew point temperatures in the 70s produced apparent temperatures or heat indices values as high as around 105 in Philadelphia and 100 to 105 elsewhere in Eastern Pennsylvania. Most of the highest temperatures occurred on the 10th, except in the Poconos where the highest temperatures occurred on the 9th. The highest apparent temperatures occurred on both the 7th and the 10th.
The excessive heat also caused many heat related injuries across the state. Many cooling centers were opened to assist senior citizens. The heat also caused a few roadways to buckle. Schools were still in session. Many that did not have air conditioning dismissed children early on the 9th and 10th. A couple of schools cancelled classes. Some after school activities were cancelled outright; others were shifted to air conditioned locations. The excessive heat caused some scattered and mainly localized power outages. There was about a twenty-five percent increase in vehicle distress calls. There was also a surge in purchases of air conditioners and pools. Some air conditioners were stolen from stores. Some public pools opened earlier than scheduled. Others took to creeks around the region, including the Brandywine, Bushkill, Monocacy and Wissahickon to seek relief.
In Philadelphia, there were eighteen heat related deaths. All but one occurred in homes with no air conditioners available or on and many with windows closed. The heat wave also coincided with the Commerce Bank Triple Crown of Cycling. The heatline run by the Philadelphia Corporation for Aging was open. Caller volume was described as heavy as they counsel callers about precautions and ways to detect signs of heat stress. Meals on Wheels handed heat tip sheets. In addition to the heat related deaths, a 38-year-old man collapsed outdoors. Power outages occurred on Gordon Street.
In Delaware County, a fourteen month old boy died after he was left in the backseat of a vehicle for about five hours in Marple Township on the 8th in the Lawrence Park Shopping Center. Also on the 8th, residents from the second floor of the Haverford Nursing and Rehabilitation Center were evacuated after the air conditioning failed. Several residents had to be hospitalized. Air conditioned senior citizen centers throughout the county had extended hours. In Haverford Township, the heat buckled a storm drain.
In Montgomery County, a 65-year-old man died in Pottstown from the heat on the 10th. The county issued a Code Red Hot Weather Health Warning. In Chester County, hospitals noted about a 20 percent increase in patient volume; most were with cardiac problems. Bucks County opened three air conditioned senior citizen centers.
In Berks County, several people sought treatment from heat related problems at the Reading Hospital and Saint Joe Medical Center.
In the Lehigh Valley, a drowned man was found under the Hokendauqua Bridge in Whitehall Township (Lehigh Township). Metropolitan Edison set a new usage record on the 9th: 3,005 megawatts. The old record was 2,996 megawatts on August 2nd 2006.  The 9th was declared an Ozone Action Day in the Lehigh Valley. Lehigh and Northampton Transportation offered free bus rides. In Forks Township (Northampton County), one person hurt his head near the Bushkill Falls Spillway.
In the Poconos, even some schools in Monroe County dismissed children early. A man in his 30s drowned in the Lehigh Gorge in Carbon County. In Parryville (Carbon County), the Eastern Comfort Living assisted living facility was evacuated after the air conditioning failed and indoor temperatures reached the mid 90s on the 8th. Forty-seven people were evacuated, a few were hospitalized with hate related illnesses.

Highest temperatures included 99 degrees at the Northeast Philadelphia Airport, 98 degrees at the Philadelphia International Airport, 97 degrees in Reading (Berks County) and West Chester (Chester County), 96 degrees at the Lehigh Valley International Airport, Hamburg (Berks County), Valley Forge (Chester County) and Doylestown (Bucks County), 95 degrees in Willow Grove (Montgomery County), 94 degrees in Springtown (Bucks County), 93 degrees in Lehighton (Carbon County)and 89 degrees in Mount Pocono (Monroe County).
The heat wave helped June 2008 to be one of the warmest Junes on record at a number of places in Eastern Pennsylvania. At the Philadelphia International Airport, the June monthly mean temperature of 76.4 degrees (4.1 degrees warmer than normal) was the fourth warmest June on record. In Reading, the June monthly mean temperature of 74.1 degrees (4.0 degrees warmer than normal) was the 7th warmest June on record. In Mount Pocono, the June monthly mean temperature of 65.6 degrees (3.6 degrees warmer than normal) was the tenth warmest June on record. While it did not crack the top ten, the June monthly mean temperature of 71.7 degrees was 3.2 degrees warmer than normal.

Excessive Heat in BERKS, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Excessive Heat in BUCKS, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Excessive Heat in CHESTER, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Excessive Heat in CARBON, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Excessive Heat in DELAWARE, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Excessive Heat in LEHIGH, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Excessive Heat in MONROE, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Excessive Heat in MONTGOMERY, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Excessive Heat in NORTHAMPTON, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Excessive Heat in PHILADELPHIA, PENNSYLVANIA
From 07-JUN-08 09:00:00 to 10-JUN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet