Philadelphia, Pennsylvania – Bright sunshine glints off downtown buildings this late morning, but the comfortable air won’t stick around much longer. A significant warmup is already underway, and the hottest weather of the week is expected by Wednesday. Residents across southeastern Pennsylvania should use the next day to prepare before temperatures approach the century mark.
According to the National Weather Service in Mount Holly, tranquil weather continues today under high pressure, with no hazardous weather expected across the Philadelphia region. That quiet stretch gives way to a steady surge in temperatures beginning Tuesday before Wednesday reaches 99 degrees, creating the highest heat of the week. Overnight lows also climb into the middle 70s, reducing nighttime cooling and adding to heat stress.
Today’s high reaches a pleasant 86 degrees with abundant sunshine and light winds. Tuesday turns noticeably hotter as highs climb to around 92 degrees under mostly sunny skies. By Wednesday afternoon, sunshine and hot conditions combine for an expected high near 99 degrees. While no widespread thunderstorms are anticipated locally during this period, meteorologists continue monitoring active severe weather across portions of the Plains and Midwest. That unsettled pattern remains well west of Pennsylvania for now.
Expect extra demand on air conditioning by Wednesday afternoon. If you’re driving along I-95, I-76, the Schuylkill Expressway, Roosevelt Boulevard, or the Pennsylvania Turnpike, keep water in your vehicle and allow extra time if your car has been parked in direct sunlight. Outdoor workers, athletes, gardeners, and anyone attending summer events should schedule frequent breaks and stay hydrated.
Thursday remains quite warm with highs around 93 degrees before temperatures ease slightly toward the weekend. A chance of showers returns Saturday, but significant cooling appears limited.
Long-range outlooks from the Climate Prediction Center continue favoring above-normal temperatures across the Mid-Atlantic during the 6-to-10-day period, suggesting summer heat may linger beyond this week.
Five-Day Forecast for Philadelphia, PA
- Monday: Sunny. High 86°F.
- Monday Night: Clear. Low 65°F.
- Tuesday: Sunny. High 92°F.
- Tuesday Night: Clear. Low 72°F.
- Wednesday: Sunny and hot. High 99°F.
- Wednesday Night: Partly cloudy. Low 75°F.
- Thursday: Mostly sunny. High 93°F.
