🔔 Philadelphia Weather

A city on the rain–snow line

Philadelphia sits squarely between the colder Northeast and the milder South, which makes it one of the most meteorologically uncertain big cities in winter. The infamous "rain–snow line" frequently sets up right over the region, and a single storm can deliver a foot of snow to the northern suburbs while downtown gets cold rain or slush. Forecasting here is a genuine coin-toss.

Hot, humid summers

Philadelphia has a humid subtropical climate, and summers are hot and sticky. July highs average in the upper 80s°F (around 30–31°C), with the heat index frequently climbing past 95°F (35°C) when Atlantic moisture pools over the Delaware Valley. Afternoon thunderstorms are common, and the record high stands at 106°F (41°C).

Variable winters

Winters are moderate but unpredictable. Highs typically sit in the low 40s°F (around 5–6°C), and seasonal snowfall swings wildly from year to year — some winters bring barely a dusting, others a blockbuster like the 30+ inches of "Snowmageddon" in February 2010.

Spring and fall are mild and changeable, with about 42 inches (1,070 mm) of rain falling across the year. Autumn tends to be the most settled and comfortable stretch on the calendar.

The humid-continental squeeze

Philadelphia sits far enough inland to lose the ocean's moderating touch, so its summers run hotter and stickier than the shore an hour east. July dew points regularly climb into the low 70s°F (low 20s°C), and the city's concrete core traps that heat well past sunset — a classic urban heat island effect.

Winters swing between raw Atlantic damp and sharp Canadian cold. The real wildcard is the nor'easter: when a coastal storm tracks just right, Philadelphia can flip from rain to a foot of snow depending on a few degrees. Spring and fall are the sweet spots, with the cherry blossoms along the Schuylkill peaking in early April.