Measured, not vibes
Best Time to Visit Philadelphia
By measured weather comfort, the top months for Philadelphia are October, May, September — and RouteVerdict's editorial pick, which also weighs crowds and prices, is April, May, June, September, October, November. The table below is computed from ERA5 reanalysis data for 2020–2024, measured at Philadelphia (12 m elevation).
Month by month
Philadelphia weather and comfort, 2020–2024
| Month | Avg high | Wet days | Comfort | Season |
|---|---|---|---|---|
| January | 6.5°C / 44°F | 8.5 | 16 | |
| February | 8.3°C / 47°F | 7.8 | 22 | |
| March | 13.3°C / 56°F | 9 | 46 | |
| April | 17.7°C / 64°F | 9.5 | 68 | |
| May | 23°C / 73°F | 9 | 82 | Best |
| June | 28.9°C / 84°F | 8.5 | 67 | |
| July | 31.5°C / 89°F | 12.2 | 48 | Shoulder |
| August | 29.9°C / 86°F | 11.2 | 58 | Shoulder |
| September | 25.9°C / 79°F | 7.8 | 80 | Best |
| October | 20.4°C / 69°F | 6.5 | 83 | Best |
| November | 14.1°C / 57°F | 6.8 | 53 | |
| December | 8.5°C / 47°F | 8.7 | 23 |
Comfort is RouteVerdict's 0–100 score: 100·exp(−(high−23)²/162) × (1 − min(0.35, wet days × 0.02)). The full method is on the methodology page. Weather data by Open-Meteo.com (ERA5, CC BY 4.0), 2020–2024 normals. Wet day = ≥1 mm precipitation.
What the seasons are actually like
Traveling to Philadelphia month by month
Philadelphia's comfort score peaks in October at 83.4, with an average high of 20.4°C and 6.5 wet days, just ahead of May's 82 and September's 80.1. Summer (July-August) brings the hottest weather, up to 31.5°C in July, but comfort drops to 48.4 and 57.8 as humidity climbs — both are RouteVerdict's shoulder months rather than editorial picks. Winter (December–February) is the coldest stretch, with highs of 6.5–8.5°C and comfort scores of 15.5–22.6.
FAQ
Philadelphia timing questions
What is the best month to visit Philadelphia?
By measured weather comfort (ERA5 2020–2024), the top months are October, May, and September, with October scoring highest. RouteVerdict's editorial pick is April, May, June, September, October, and November, which also weighs crowds, prices, and events.
What is the hottest month in Philadelphia?
July, with an average daily high of 31.5°C (89°F).
What is the rainiest month in Philadelphia?
July, averaging 12.2 days with at least 1 mm of precipitation.
When is shoulder season in Philadelphia?
August and July — the best-scoring months outside both the measured top three and RouteVerdict's editorial peak-season pick.
Why aren't July and August in Philadelphia's editorial best months despite being warm?
July, the hottest month at 31.5°C, scores just 48.4 on comfort, and August isn't far ahead at 57.8 — both trail the October peak of 83.4, which is why they're listed as shoulder months instead.
What is Philadelphia's single best month for weather?
October, with an average high of 20.4°C, 6.5 wet days, and a comfort score of 83.4 — the highest measured for any month.