The high temperature so far at Philadelphia International Airport reached 99, breaking a record high of 98 set last year.

Extreme heat has increasingly proven fatal in the last few decades as sweltering temperatures have become more common. In 2024, a study published in the Journal of the American Medical Association identified a 117% increase in heat-related deaths from 1999 to 2023, including a steady uptick since 2016.

It's oppressive outside today in Pennsylvania, as heat indices may near 110 degrees. When is relief on the way? Here's the forecast, heat maps, more.