PHILADELPHIA, Pa. – A stretch of classic fall weather holds steady across southeastern Pennsylvania, but fog and midweek rain may disrupt early commutes by Tuesday. Mild afternoons and crisp nights will dominate through Monday before a stronger system brings showers and a few thunderstorms Tuesday evening.
According to the National Weather Service in Mount Holly, patchy fog is expected to form along the I-95 corridor both Monday and Tuesday mornings, reducing visibility for early drivers. Commuters are urged to allow extra time, especially in low-lying areas near the Schuylkill River and the Delaware waterfront. Sunshine will return briefly before clouds increase Tuesday afternoon ahead of a frontal boundary.
Daytime highs will stay near 80°F early this week — nearly ten degrees above normal for early October. However, cooler air will follow the front by midweek, bringing a noticeable fall feel by Wednesday. The NWS reports a 70–80% chance of showers Tuesday night, with rainfall totals up to a quarter-inch possible. Motorists should prepare for slick conditions and possible ponding on secondary roads.
The pattern will quickly stabilize, leaving behind ideal conditions for fall outings later in the week. Thursday and Friday look seasonably mild and sunny, perfect for Halloween decorating or visiting local farms and pumpkin patches across Montgomery and Chester Counties.
Residents should continue monitoring updated forecasts from the NWS and PennDOT travel alerts for fog and wet road conditions Tuesday morning.
Five-Day Forecast for Philadelphia, PA:
Sun: 83/56 – Sunny, light breeze; mild fall day.
Mon: 80/60 – Partly sunny; patchy fog early.
Tue: 81/63 – Increasing clouds; evening showers possible.
Wed: 70/49 – Cooler with lingering showers; breezy later.
Thu: 65/47 – Sunny, crisp air returns; pleasant fall day.
