September · United States
Best time to visit Philadelphia in September Weather, crowds & prices
Weather in Philadelphia in September
Average temperature 21°C, 101 mm of rain, about 24 days with 6+ hours of sunshine and 70% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
8.2/10
Ranked #4 of 12 months
- Avg temp
- 21°C
- Rainfall
- 101 mm
- Humidity
- 70%
- Days with 6h+ sun
- 24
- Crowd Density
- Moderate Crowds
- Average Expenses
- $$ · Moderate Cost ($$)
September in Philadelphia scores 8.2/10 for sightseeing and cultural travel - an above-average month (#4 of 12). Expect around 21°C, 101 mm of rain, and roughly 24 days with 6+ hours of sunshine this month.
Independence Hall history and mural-lined neighborhoods feel finest May through September.
September in Philadelphia — reliably good (4th best month)
At 21°C (70°F) this is comfortable city weather in September, with sightseeing easiest before lunch and after the afternoon peak.
101 mm of rain makes this a wet month here, though with about 24 days with 6+ hours of sunshine there is still bright weather between the fronts.
That is 8.2/10 on the same scale — 4th of 12 months, versus 8.5/10 for the best month here.
Pack light clothing, a hat and real sun protection, a proper rain shell rather than an umbrella.
Expect mid-season pricing, and crowds are moderate.
Frequently asked
- What is the weather like in Philadelphia in September?
- In September, Philadelphia averages 21°C, 101 mm of rain, and about 24 days with 6+ hours of sunshine. Its climate-comfort score is 8.2/10.
- Is September a good time to visit Philadelphia?
- September earns a 8.2/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Philadelphia in September?
- Expect about 101 mm of rain in September. Average humidity is 70% and there are about 24 days with 6+ hours of sunshine.
Curated in Philadelphia
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Things to do in Philadelphia
Philadelphia, United States. Live activities and tours from GetYourGuide, matched to this destination.