The Lehigh Valley will be under a heat advisory starting Thursday morning, with temperatures in the 90s and a heat index of over 100 degrees.
The National Weather Service is also warning of storms that could bring winds and brief downpours over the next few days.
A high of 85 is expected Wednesday, followed by highs of 93 both Thursday and Friday, according to the National Weather Service in Mount Holly, New Jersey. The Lehigh Valley, as well as neighboring Berks and Upper Bucks counties, will be under a heat advisory from 11 a.m. Thursday until 8 p.m. Friday.
Heat index values of up to 101 are possible, according to forecasters. Temperatures and high humidity could cause illnesses. Temperatures will still be warm over the weekend, but not nearly as humid.
“A cold front is forecast to move through the region late Friday, which is expected to knock temperatures and dewpoints down several degrees,” meteorologists wrote Wednesday in their daily forecast discussion. “Though it will still be hot with highs upper 80s to low 90s over the weekend, dewpoints will return to more comfortable levels, minimizing the threat for additional heat headlines.”
Storms are possible Wednesday through Friday. There is an 80% chance of showers or storms Wednesday, and up to a 10th of an inch of rain could fall. The region is at a marginal risk for severe weather.
Storms could produce damaging winds and hail between 4 and 10 p.m., the weather service said.
⛈️ Scattered showers and storms are forecast to develop this afternoon and evening. A few storms could be strong to severe, with locally damaging winds and brief heavy downpours possible. #PAwx #NJwx #DEwx #MDwx pic.twitter.com/OY1RSZFZsK
— NWS Mount Holly (@NWS_MountHolly) June 10, 2026
Thunderstorms could come to the area Thursday and Friday as well. Forecasters said damaging winds will be the main threat, but large hail and a brief tornado can’t be ruled out Thursday. Any showers or storms would come later in the day, according to the weather service.
Saturday and Sunday should be clear. Rain is possible again early next week.
Here is the extended forecast from the National Weather Service:
Thursday: A chance of showers and thunderstorms between 3 and 5 p.m., then showers likely and possibly a thunderstorm after 5 p.m. Partly sunny, with a high near 93. West wind 5 to 10 mph. Chance of precipitation is 60%. New rainfall amounts of less than a 10th of an inch, except higher amounts possible in thunderstorms.
Friday: Showers likely and possibly a thunderstorm after 2 p.m. Partly sunny, with a high near 93. West wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a 10th and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday: Sunny, with a high near 88.
Sunday: Sunny, with a high near 91.
Monday: A chance of showers. Partly sunny, with a high near 83. Chance of precipitation is 40%.
Tuesday: A chance of showers. Partly sunny, with a high near 81. Chance of precipitation is 40%.