Philadelphia weather in May
May in Philadelphia: nice, rainy — one of the best months to visit.
#1 of 12 months in Philadelphia · #80 of 604 destinations to visit in May · comfort 90/100 (tier S)
Updated June 2026 · climate normals from ERA5 reanalysis
Philadelphia climate normals — May
| Daytime high | 22°C / 72°F | 😎 nice |
|---|---|---|
| Nighttime low | 12°C / 54°F | |
| Feels like (high) | 22°C / 72°F | |
| Rainfall | 101 mm / 4 in | 🌧 rainy |
| Rainy days | 12 days | |
| Humidity | 66% | 💧 humid |
| Dew point | 10°C / 50°F | |
| Sunshine | 10.4 h/day | |
| Daylight | 14.4 h | |
| Wind | 17 km/h / 10 mph | |
| Air quality (US AQI) | 53 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Philadelphia in May — FAQ
- Is May a good time to visit Philadelphia?
- May in Philadelphia: nice, rainy — one of the best months to visit. It ranks #1 of 12 months for Philadelphia on SeasonMap's comfort score (90/100).
- What is the weather like in Philadelphia in May?
- In May, Philadelphia averages a daily high of 22.4°C and a low of 12.3°C, with about 100.6 mm of rain over roughly 11.6 rainy days.
- What is the air quality in Philadelphia in May?
- Philadelphia has a mean US Air Quality Index of about 53 in May.