Philadelphia weather in May
In May, Philadelphia has an average high of 22 °C72 °F and an average low of 11 °C52 °F, with about 96 mm3.8 in of precipitation. It is the 5th warmest month of the year and ranks 9th for precipitation.
How May compares with other months
Compared with April, May is 5.7 °C10.2 °F warmer on average. Compared with June, May is 5.1 °C9.2 °F cooler on average and drier by 25 mm1.0 in. Daylight lasts about 14.4 hours around the middle of the month. Average relative humidity is 79% and the average cloud amount 61%.
Is May a good time to visit Philadelphia?
Yes — May is one of the most comfortable months to visit Philadelphia by our comfort score, which favours average highs of 21–28 °C, lows above 5 °C, little rain and moderate humidity.
What to wear in May
For Philadelphia in May, pack light layers — T-shirts plus a light sweater or jacket, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
May in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Philadelphia | 2272 | 1152 | 963.8 |
| Allentown | 2272 | 1051 | 1034.1 |
| Atlantic City | 1966 | 1254 | 893.5 |
| Staten Island | 2170 | 1151 | 983.9 |
| Brooklyn | 1763 | 1253 | 1014.0 |
| New York City | 1763 | 1253 | 1014.0 |
| Paterson | 2271 | 1051 | 1014.0 |
| Manhattan | 2069 | 1050 | 983.8 |
| Baltimore | 2374 | 1254 | 1064.2 |
Nearby places that are more than 1 °C1.8 °F warmer in May: Baltimore; cooler: Atlantic City, Brooklyn, New York City and Manhattan.
Other months in Philadelphia
- January3 °C38 °F / −5 °C23 °F
- February5 °C41 °F / −4 °C24 °F
- March10 °C50 °F / −1 °C31 °F
- April17 °C63 °F / 5 °C41 °F
- May22 °C72 °F / 11 °C52 °F
- June27 °C81 °F / 17 °C62 °F
- July30 °C86 °F / 20 °C67 °F
- August30 °C85 °F / 19 °C66 °F
- September26 °C79 °F / 15 °C59 °F
- October19 °C67 °F / 8 °C47 °F
- November12 °C54 °F / 2 °C36 °F
- December7 °C44 °F / −2 °C28 °F
Frequently asked questions
How warm is Philadelphia in May?
In May the average high in Philadelphia is 22 °C (72 °F) and the average low is 11 °C (52 °F).
Does it rain a lot in Philadelphia in May?
On average about 96 mm (3.8 in) of precipitation falls in May; it ranks 9th of the 12 months.
Is May the warmest month in Philadelphia?
No. The warmest month in Philadelphia is July, with an average high of 30 °C (86 °F). The coldest month is January, with an average low of -5 °C (23 °F).
How long is the day in Philadelphia in May?
In the middle of May the day in Philadelphia lasts about 14.4 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Philadelphia in May?
The average relative humidity in May is about 79%. This is a long-term average for the whole day.
How cloudy is Philadelphia in May?
On average about 61% of the sky is covered by cloud in May. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.