If you have outdoor plans this weekend, be aware that you are likely going to sweat–a whole lot–unless you’re lucky enough to be at the beach or in a swimming pool.
The National Weather Service has issued an excessive heat warning for much of eastern Pennsylvania–including the Lehigh Valley–for Saturday from noon to 9 p.m., for heat index values that could reach 110 degrees F. The heat index is a measurement of air temperature and relative humidity which approximates what the outside temperature actually feels like.
The high temperature in Hellertown Saturday is forecast to be in the mid 90s–which isn’t close to record-breaking–but with humidity of 60 to 70 percent it will feel about 15 degrees hotter than it is.
An excessive heat warning means “a prolonged period of dangerously hot temperatures and high humidity levels will occur,” the NWS statement issued Friday said. “The conditions will enhance the development of heat-related health issues among susceptible individuals. Be sure to drink plenty of fluids, stay in an air-conditioned environment if possible, stay out of the sun and check on elderly relatives and neighbors.”
The heat wave is forecast to last at least through Sunday, when highs will still be in the 90s and humidity levels will remain high. The forecast heat index on Sunday afternoon is 102 to 107 in the Lehigh Valley, according to the National Weather Service.
On Monday temperatures are forecast to drop slightly, with a high of 89 predicted.
There is a 30-50 percent chance of strong thunderstorms Saturday through Monday.
