Philadelphia is waking up to a cloudy, muggy Sunday, with patchy fog hanging on near dawn and temperatures hovering around 72°F. Forecasters expect the fog to thin after midmorning, giving way to mostly cloudy skies, a slight chance of showers or an isolated thunderstorm, and a high near 83°F.
Extreme Heat Watch For The Holiday Week
The National Weather Service office in Mount Holly has issued an Extreme Heat Watch from Wednesday, July 1, through Saturday, July 4, warning of multiple days of dangerously hot, humid conditions. Highs are expected to climb into the mid 90s to the low 100s, with Thursday and Friday currently forecast near 103°F, and heat index values could reach 100 to 110°F. The watch is meant to signal an elevated risk of heat-related illness and to encourage precautions for older adults, outdoor workers and people without air conditioning.
What That Means Locally
City agencies advise residents to seek out air-conditioned spaces and note that cooling centers and special heat services are activated during heat emergencies. Call 311 to find a cooling center or reach the PCA Heatline at (215) 765-9040 for health guidance, according to the City of Philadelphia. Officials also urge people not to leave children or pets in parked cars, to drink plenty of fluids, and to schedule heavy outdoor work for early morning or evening hours.
When To Change Plans
From Wednesday through Friday, it is smart to avoid strenuous outdoor activity during the midday heat, when humidity will make the air feel even hotter and raise the risk of heat exhaustion or heat stroke. Thunderstorm chances return around Friday and through the holiday weekend and could interrupt outdoor events. For more background on the setup, see our earlier coverage on how Philly is set to sizzle.
Quick Forecast Snapshot
Monday is expected to warm into the upper 80s, Tuesday near 90°F, and Wednesday around 97°F. Thursday and Friday are currently forecast to peak near 100 to 103°F before easing slightly over the weekend. Keep an eye on the National Weather Service and ReadyPhiladelphia alerts for any upgrades from watches to warnings.
Basic precautions still matter: drink water, take breaks in cool places, check on older neighbors and never leave people or pets unattended in cars. If you need help locating services, call 311 or the PCA Heatline. City guidance and National Weather Service information will be updated through the week.
