Heat in Pennsylvania

Events

700

Deaths

318

Injuries

344

Damage

None recorded

• Heat in Pennsylvania, July 4 to 6, 199974 deaths · 135 injured · 10 eventsA very strong and oppressive high pressure system that extended from the surface to aloft gave Eastern Pennsylvania a brutal heat wave that included the entire Independence Day weekend. There were 74 heat related deaths and over 100 reported heat related injuries.
• Heat in Pennsylvania, July 12 to 18, 199724 deaths · 60 injured · 10 eventsThe longest and hottest heat wave of the summer of 1997 brought around 6 consecutive days of high temperatures of 90 degrees or higher to Eastern Pennsylvania. Along with the oppressive heat came high humidity levels and limited rainfall.
• Heat in Pennsylvania, August 1 to 3, 200624 deaths · 40 injured · 8 eventsA strong area of high pressure anchored over the East Coast and the western Atlantic, resulted in a stretch of excessive heat for the entire region to start off August 2006.
• Heat in Pennsylvania, August 6 to 10, 200122 deaths · 10 eventsA ridge of high pressure both surface and aloft that was broiling the central part of the country moved east and covered Eastern Pennsylvania during the work week of August 6th. This brought a very oppressive hot spell to the region and peaked on the 9th.
• Heat in Pennsylvania, July 1 to 4, 200215 deaths · 8 eventsJuly started with unseasonably hot and humid weather across Eastern Pennsylvania. The hottest and most humid weather occurred on Independence Day before a cold front quietly moved through the region during the night of the 4th.
• Heat in Pennsylvania, July 20 to 23, 199811 deaths · 75 injured · 6 eventsA heat wave affected Southeast Pennsylvania from July 20th through the 23rd. Eleven persons died (Eight in Philadelphia and three in Montgomery County.) from the heat. They were usually discovered in homes with closed windows and inadequate ventilation.
• Heat in Pennsylvania, August 1 to 5, 20029 deaths · 10 eventsThe excessive heat that began on July 28th continued through August 5th. The combination of high temperatures in the 90s and high dew points produced heat indices of over 100 each day through the 5th. A cold frontal passage late in the day on the 5th ended the excessive heat.
• Heat in Pennsylvania, August 11 to 20, 20028 deaths · 10 eventsThe longest run of days with high temperatures of 90 or greater this summer occurred across Eastern Pennsylvania from the 11th through the 20th. This was the longest heat wave for the state since the twelve day heat wave during the summer of 1999.
• Excessive Heat and Heat in Pennsylvania, July 4 to 7, 20128 deaths · 8 eventsBoth excessive heat and more humidity returned to most of Eastern Pennsylvania starting on Independence Day and lasted until the 7th. The excessive heat claimed the lives of eight people, five within Philadelphia and three in Lehigh County.
• Heat in Pennsylvania, July 25 to 27, 20057 deaths · 8 eventsThe most hottest and humid air mass of the summer so far occupied Eastern Pennsylvania from the 25th through the 27th.
• Heat in Pennsylvania, May 6 to 9, 20007 deaths · 2 eventsThe first run of hot weather, with high temperatures that reached between 90 ands 95 degrees for up to four days across southeast Pennsylvania caused seven heat related deaths.
• Heat in Pennsylvania, July 18 to 19, 20056 deaths · 5 eventsA hot and very humid air mass enveloped southeastern Pennsylvania on the 18th and 19th. High temperatures reached into the lower 90s, but dewpoint temperatures were in the mid 70s. The combination produced afternoon heat indices of between 100 and 105.
• Heat in Pennsylvania, August 1, 19995 deaths · 8 eventsA protracted run of days with consecutive high temperatures of 90 degrees or higher began on July 23rd in Southeast Pennsylvania. It lasted as long as 16 days near the Maryland border through August 7th.
• Heat in Pennsylvania, August 2 to 5, 20055 deaths · 8 eventsAnother run of unseasonably hot weather affected eastern Pennsylvania from August 2nd through the 5th. High temperatures reached at least into the mid 90s each afternoon. The heat resulted in five more heat related deaths (4 in Philadelphia, 1 in Montgomery County).
• Heat in Pennsylvania, July 27 to 28, 19975 deaths · 2 eventsA brief two day hot spell claimed the lives of 5 more persons in the Philadelphia Metropolitan Area. Four persons died within Philadelphia. The 5th death occurred in Pottstown in Montgomery County where a 61-year-old woman was found dead in a home with all the windows closed.
• Heat in Pennsylvania, August 7 to 10, 20005 deaths · 1 eventAn unseasonably hot and extremely humid air mass was over the city of Philadelphia during most of the work week of August 7th. High temperatures reached into the lower 90s from the 7th through the 10th in and around Philadelphia.
• Heat in Pennsylvania, July 29, 20115 deaths · 1 eventAnother unseasonably hot and humid day claimed the lives of five people within Philadelphia. The high temperature at the Philadelphia International Airport reached 96 degrees and the afternoon heat index reached between 100F and 105F.
• Heat in Pennsylvania, July 23 to 31, 19994 deaths · 8 eventsA protracted run of days with consecutive high temperatures of 90 degrees or higher began on July 23rd in Southeast Pennsylvania. It lasted as long as 16 days near the Maryland border through August 7th.
• Heat in Pennsylvania, June 24 to 27, 20024 deaths · 5 eventsThe first prolonged period of heat and humidity of the season claimed the life of four people in Southeast Pennsylvania. A 9-year-old girl suffering from cerebral palsy and asthma died of heat stroke while at Sesame Place in Langhorne (Bucks County).
• Heat in Pennsylvania, July 4 to 9, 20034 deaths · 5 eventsA Bermuda high pressure system at both the surface and aloft gave Southeastern Pennsylvania a six day run of high temperatures in the 90s and dew point temperatures in the 70s. The two hottest days were July 4th and 5th.
• Heat in Pennsylvania, June 21 to 26, 19974 deaths · 2 eventsThe first heat wave of 1997 brought the hottest weather in two years to the Philadelphia area. The highest temperatures reached near 100 degrees on the 25th. Four persons died of hyperthermia within the city. Three died on the 26th, the last day of the heat wave.
• Heat in Pennsylvania, July 28 to 30, 20023 deaths · 8 eventsAnother hot and very humid air mass moved into Eastern Pennsylvania on the 28th. In most areas this hot spell produced some of the highest heat indices of the summer as they reached near 105F and between 105F and 110F in Philadelphia during the afternoon of the 29th.
• Heat in Pennsylvania, June 25 to 26, 19983 deaths · 5 eventsExcessive heat for two days brought some of the highest temperatures of the summer and caused three heat related deaths in Southeast Pennsylvania. The hot weather ended abruptly with severe thunderstorms during the late afternoon of the 26th.
• Heat in Pennsylvania, June 23 to 27, 20033 deaths · 5 eventsThe first run of excessive heat and humidity of the summer season occurred during the work week of June 23rd across Philadelphia and its suburbs. The highest temperatures and heat indices occurred on the 26th.
• Heat in Pennsylvania, June 13 to 14, 20053 deaths · 5 eventsThe first run of unseasonably hot and humid weather for the summer season on June 13th and 14th caused a few heat related deaths within Philadelphia and early dismissals for many schools that did not have air conditioners.

Heat everywhereEvery kind of event in Pennsylvania

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24.