A Heat Advisory remains in effect for parts of eastern Pennsylvania from 11 a.m. Thursday through 8 p.m. Friday, according to the National Weather Service in Mount Holly.
The advisory includes Berks, Lehigh, Northampton, Upper Bucks, Western Chester and Western Montgomery counties.
Forecasters say heat index values could reach up to 102 degrees, creating dangerous conditions for people spending extended time outdoors.
The National Weather Service says hot temperatures combined with high humidity may cause heat-related illnesses. Residents are urged to drink plenty of fluids, stay in air-conditioned areas when possible, avoid prolonged sun exposure, and check on relatives and neighbors.
Anyone working or spending time outside should wear lightweight, loose-fitting clothing and try to limit strenuous activity to the early morning or evening hours.
Some showers and thunderstorms are possible late Thursday afternoon and again late Friday afternoon, which may bring brief local relief. However, humid conditions are expected to continue until a cold front brings much less humid air into the region this weekend.
For Thursday, there is a chance of showers and thunderstorms, mainly after 5 p.m. Some storms could be severe. Patchy fog is possible before 9 a.m. Otherwise, conditions are expected to be partly sunny, with a high near 93 degrees. Winds will be out of the west at 5 to 10 mph. The chance of precipitation is 30%, with new rainfall amounts generally less than a tenth of an inch, except for higher amounts possible in thunderstorms.
Thursday night, showers and thunderstorms are likely, mainly before 11 p.m. Some storms could be severe. Skies will remain mostly cloudy, with a low around 69 degrees. Winds will be out of the west around 5 mph, becoming calm in the evening. The chance of precipitation is 60%, with new rainfall amounts between a tenth and a quarter of an inch, except for higher amounts possible in thunderstorms.
Heat exhaustion and heat stroke can become serious quickly. Anyone experiencing dizziness, heavy sweating, weakness, nausea, confusion, or fainting should move to a cooler place and seek medical help if symptoms worsen.
