Philadelphia Geography & Climate

Philadelphia sits on a low neck of land between the Delaware River and the Schuylkill, about a hundred miles upriver from the sea — far enough inland to be defensible, deep enough to remain one of the country's major freshwater ports.

The centre is almost entirely flat, which is why the grid works and why the city is so walkable. The land rises gently to the northwest, where the Schuylkill cuts through and the terrain becomes properly hilly around the park.

Fairmount Park follows the Schuylkill through the middle of the city and is among the largest urban park systems in the United States, with the river trail running for miles out of town.

The city is the fall line in practice: above it the river is rocky and shallow, below it navigable, which is the entire reason a port grew here.

Philadelphia sits at the boundary of humid subtropical and humid continental and gets a full four seasons.

Summers are hot and humid, regularly into the low thirties Celsius, with afternoon thunderstorms. The brick and asphalt hold the heat into the evening.

Winters are cold, with a few real snowfalls a year and occasional nor'easters that shut the city briefly.

Spring and autumn are the good seasons, and autumn is the more reliable of the two — October is consistently the best month of the year.

Remnants of Atlantic hurricanes reach the city in late summer, bringing heavy rain and river flooding rather than wind.