Philadelphia Weather in September

With daytime temperatures of 26°C (79°F) and nighttime lows of 17°C (63°F), September in Philadelphia brings high temperatures during the day. Do keep in mind that quite a bit of rainfall is typical. Around 108 mm (4.3 in) falls on average.

Rainfall in Philadelphia in September

Looking at the last 30 years, the data shows about 8 days with rain, averaging 108 mm (4.3 in) for the month. The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.

Temperature in Philadelphia in September

In September, expect high temperatures in Philadelphia, with highs of 26°C (79°F) and lows of 17°C (63°F) at night. Conditions stay fairly consistent through the month, making it easier to plan what to wear. At 17°C (63°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping.

Sunshine in Philadelphia in September

The days are predominantly sunny, with an estimated total of around 218 hours of sunshine. These sun-filled days are perfect for playing sports, visiting parks, or going for a bike ride.

Average water temperature in September

The water is 22°C (72°F) this month, warm enough that getting in requires no effort at all. Good conditions for swimming, snorkeling, or just floating around.

If your ideal day consists of dry skies and pleasant temperatures, May typically offers the best circumstances for Philadelphia.