Philadelphia woke up under a blanket of patchy fog and muggy 70°F air this morning, with visibility knocked down in spots near rivers and bays. The haze should burn off by midmorning as most neighborhoods warm into the upper 80s. After that, things get serious: a multi-day heat event later this week is lining up to roast holiday plans.
Fog Lifts, Warm Monday
Patchy fog is expected before 8 a.m., then skies turn mostly sunny with a high near 88°F and light east winds. Humidity stays on the more comfortable side today, but that break will not last as the week wears on.
Extreme Heat Watch From Wednesday Through Saturday
The National Weather Service has issued an Extreme Heat Watch for the Delaware Valley from Wednesday afternoon through Saturday evening (Wednesday, July 1, through Saturday, July 4, 2026), covering Philadelphia and surrounding counties. Forecast highs climb into the upper 90s on Wednesday and then into roughly 100–105°F on Thursday and Friday, with heat-index values possibly near 105–110°F and overnight lows stuck in the mid-70s to low-80s, offering little relief. Those numbers raise the risk of heat-related illness and could challenge local records. Residents are urged to keep an eye on the National Weather Service for any upgrades from watches to warnings and for updated timing.
Plan Ahead And Stay Cool
City officials are urging residents without air conditioning to head for cooling centers, libraries, pools or other air-conditioned public spaces. Callers can reach the PCA Heatline at 215-765-9040 or dial 311 for help finding services. To cut your heat risk, avoid strenuous outdoor activity during the midday hours, never leave children or pets in parked cars, and drink plenty of water, according to the City of Philadelphia.
Thunderstorm Chances Late Week
Scattered afternoon and evening thunderstorms become more likely starting Friday and could easily upend some Fourth of July barbecues and fireworks plans. Any storms that pop up may bring gusty winds and brief heavy rain. Keep checking local forecasts through the holiday and be ready to pivot those outdoor plans if watches or warnings are issued.
