Philadelphia is locked under an Extreme Heat Warning through 8 p.m. Saturday, July 4, 2026, with clear skies and temperatures already hovering near 83°F this morning. Forecast highs are expected to surge into the low 100s today, and heat-index values could spike to around 110°F, making it a dangerous day outdoors for older adults, children, and anyone without reliable air conditioning. Overnight lows in the upper 70s to low 80s will offer almost no relief.
What To Expect Today
Today brings full sun and a blistering high near 104°F, with northwest winds of 5 to 10 mph offering little more than a token breeze. A few isolated showers or thunderstorms could pop up after about 5 p.m., but coverage is expected to be spotty. The National Weather Service Mount Holly reports that heat-index values may reach as high as 111°F this afternoon and has the Extreme Heat Warning posted through 8 p.m. Saturday, July 4, 2026.
If you have to be outside, shift heavy exertion to early morning or evening, take frequent breaks in the shade or air conditioning, and do not push through symptoms like dizziness or nausea.
Weekend Outlook
Saturday keeps the heat cranked up, with a high around 101°F and scattered afternoon thunderstorms possible after 2 p.m. Any rain that does fall should stay on the lighter side in most neighborhoods. Sunday is expected to ease the temperatures a bit, with highs slipping into the upper 80s to around 90°F as more showers and thunderstorms move in. Showers then become likely Sunday night into Monday.
Monday looks cooler with highs near 85°F, but showers and thunderstorms remain in the picture and could complicate holiday plans. Any storm that develops at any point this weekend may bring brief heavy rain and gusty winds.
City Response And Cooling Help
The City of Philadelphia has declared a Heat Health Emergency and opened more than 50 cooling centers with extended hours. Residents can call 311 or the Philadelphia Corporation for Aging Heatline at 215-765-9040 for cooling center locations, wellness checks, and guidance.
City crews are also ramping up water and ice distribution at major event sites and will staff medical tents along the Parkway for July 4 events. For background on how this heat wave built up, see how the July 4 heat blast hit Philly.
Heat And Air Quality Safety
A code orange air quality alert is in effect for the Philadelphia metro area, meaning people with asthma, heart disease, or other lung conditions should limit heavy outdoor activity during the afternoon when pollution levels peak.
Everyone is urged to drink water regularly, wear lightweight and light-colored clothing, and avoid direct sun during the hottest part of the day. Never leave children or pets in parked cars, even for a short errand. If someone shows signs of heat stroke, including confusion, fainting, or seizures, move them indoors, try to cool them down, and call 911 immediately.
Employers with outdoor crews should schedule frequent breaks in shaded or air conditioned areas, provide plenty of water, and consider shifting the most strenuous tasks to cooler hours. Residents are encouraged to monitor local alerts, check on vulnerable neighbors, and plan any outdoor activities for early morning or late evening when conditions are less extreme.
