Philadelphia, Pennsylvania – Triple-digit heat returns to Philadelphia on Tuesday, July 29th, driving temperatures and humidity to dangerous levels just as the city heads into the heart of summer. With a heat index topping 104 degrees, residents and commuters on I-95, Route 76, and across the Delaware Valley should brace for serious heat hazards and stay alert for public health warnings.
According to the National Weather Service in Mount Holly, a Heat Advisory remains in effect from 11 a.m. Tuesday through 8 p.m. Wednesday for Philadelphia and much of southeastern Pennsylvania, including Bucks, Montgomery, Chester, and Delaware counties. The heat index—what it feels like when temperature and humidity combine—could spike as high as 104°. The NWS warns that this level of heat and humidity can quickly lead to heat exhaustion or even heat stroke, especially for vulnerable groups and anyone working or exercising outdoors.
Expect sluggish traffic on major roads as vehicles overheat and pavement temperatures soar. SEPTA and regional rail riders should plan for delays and possible service changes. All Philadelphians are urged to drink plenty of water, seek air-conditioned spaces, avoid strenuous activity during the afternoon, and check on neighbors who may not have cooling. City-run cooling centers will open by midday, and city pools offer extended hours.
The high heat continues Wednesday before relief arrives with possible showers and thunderstorms Wednesday night and Thursday. Looking ahead, Friday brings a slight chance of afternoon rain, while Saturday and Sunday usher in more comfortable summer weather, with highs returning to the low 80s and plenty of sunshine.
Stay tuned as additional advisories are possible. The city will update cooling center locations and service alerts as conditions develop. Heat advisories remain in effect until at least 8 p.m. Wednesday.
Philadelphia Five Day Weather Outlook: Tuesday, July 29 – Sunday, August 3
- Tuesday: Sunny and hot, high near 97°. Heat index up to 103°. Southwest wind 5 mph.
- Wednesday: Mostly sunny, high near 96°. Heat index up to 104°. Showers possible late (40% chance) with a low around 76°.
- Thursday: Chance of showers and thunderstorms (60%), high near 87°. Rain likely by afternoon and evening. Cooler overnight, low 68°.
- Friday: Partly cloudy, high near 78°. Scattered showers possible early. Low 64°.
- Saturday: Mostly sunny and milder, high near 80°. Low 62°.
- Sunday: Sunny, seasonable, high near 83°. Low around 64°.
Prepare for dangerous heat through midweek, then look forward to a milder, sunny weekend across Philadelphia.
