Philadelphia, Pa. – A muggy heat wave will grip the Philadelphia region by midweek, with thunderstorms and potentially dangerous heat indices expected through Thursday.
According to the National Weather Service in Mount Holly, temperatures will climb from the upper 60s on Tuesday into the 90s by Thursday, with humidity pushing heat indices to 100°F across much of eastern Pennsylvania and New Jersey. Isolated severe storms are likely Wednesday afternoon and again on Thursday, particularly during peak heating hours.
Tuesday will bring scattered showers and a 30–70% chance of afternoon thunderstorms. Cloud cover and damp air will dominate early, but conditions will rapidly shift. On Wednesday, skies clear somewhat as highs rise into the low 90s, and severe storms could develop late in the day. Thursday continues the hot, humid trend, with another round of potentially damaging storms in the afternoon and evening.
Beachgoers in New Jersey should take extra caution — a moderate rip current risk is in place Tuesday, with life-threatening currents possible.
Residents should stay hydrated, limit outdoor activity during peak heat, and have a plan in case of sudden storms or power outages. Heat advisories may be issued later this week.
☀️ 3-Day Forecast Snapshot (Philadelphia area):
- Tuesday (6/17): 67–80°F, mostly cloudy, showers & t-storms (30–70%)
- Wednesday (6/18): 80–92°F, partly sunny, humid, PM severe storms possible
- Thursday (6/19): 82–93°F, hot, very humid, PM storms, heat index up to 100°
