The National Weather Service has issued a heat advisory for York County through 8 p.m. Saturday.
High temperatures and humidity will take heat index values above 100 degrees over the next 24 hours, the weather service said.
Meanwhile, the state Department of Environmental Protection is forecasting a code orange air quality action day for the area on Saturday and Sunday.
On such days, young children, the elderly and those with respiratory problems should limit outdoor activities. And code orange action day indicates unhealthy pollution levels for sensitive people.
As for the forecast, the weather service is predicting a high of 95 on Saturday and Sunday with a chance of showers and thunderstorms both days.
The best chance of precipitation is Saturday night, when there's a 40 percent chance of rain.
High temperatures will continue to hover around 90 degrees through the July 4 holiday.