After several comfortable days, a weekend heat wave is forecast to impact our area, with high temperatures in the low to mid 90s Saturday through Monday and heat indexes of up to 105 possible, according to meteorologists.

The National Weather Service (NWS) said Tuesday in a hazardous weather outlook statement that “heat index values may reach between 100 and 105 degrees Sunday afternoon away from the coast. Peak heat indices in the upper 90s to around 100 degrees are possible during the afternoon hours on Saturday and Monday.”

High temperatures Saturday through Monday are forecast by the NWS to be 94, 95 and 92, respectively.

The regional weather website PA Weather Action is forecasting peak heat indices in the Lehigh Valley of 100 and 105 on Saturday and Sunday, respectively.

“Sunday will be the most unbearable (day), with heat index values in many areas throughout the state above 100 degrees,” lead forecaster Josh Adams said in a post published Tuesday. “Urban areas of Southeast PA may be even hotter, with values as high as 106. Bring several water bottles if you plan to be outside for more than an hour.”

Heat and humidity are expected to continue well into next week, with high temperatures in the upper 80s to low 90s and high humidity levels expected in advance of the Independence Day holiday.

Some popular places to cool off on hot summer days in the Saucon Valley include the Hellertown Pool, which is open daily from noon to 7 p.m. (weather permitting), and Lost River Caverns, where the temperature underground is a constant 52 degrees, year-round. Call it Mother Nature’s air conditioning.