Philadelphia weather in December
In December, Philadelphia has an average high of 7 °C44 °F and an average low of −2 °C28 °F, with about 111 mm4.4 in of precipitation. It is the 10th warmest month of the year and ranks 4th for precipitation.
How December compares with other months
Compared with November, December is 5.1 °C9.1 °F cooler on average and wetter by 21 mm0.8 in. Compared with January, December is 3 °C5.5 °F warmer on average and wetter by 33 mm1.3 in. Daylight lasts about 9.3 hours around the middle of the month. Average relative humidity is 85% and the average cloud amount 63%.
Is December a good time to visit Philadelphia?
December is not among the most comfortable months by our comfort score: it is cool (average high 7 °C44 °F), nights are cold (average low −2 °C28 °F) and it is fairly wet (111 mm4.4 in). The most comfortable months in Philadelphia are May and September.
What to wear in December
For Philadelphia in December, pack a warm coat, layers and closed shoes, shoes with good grip, as frost is common and an umbrella or light rain jacket.
December in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Philadelphia | 744 | −228 | 1114.4 |
| Allentown | 541 | −326 | 1044.1 |
| Atlantic City | 846 | 236 | 1194.7 |
| Staten Island | 643 | −129 | 1154.5 |
| Brooklyn | 744 | 236 | 1335.2 |
| New York City | 744 | 236 | 1335.2 |
| Paterson | 541 | −327 | 1114.4 |
| Manhattan | 541 | −228 | 1164.6 |
| Baltimore | 643 | −229 | 963.8 |
Nearby places that are more than 1 °C1.8 °F warmer in December: Atlantic City, Brooklyn and New York City; cooler: Allentown and Paterson.
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 December?
In December the average high in Philadelphia is 7 °C (44 °F) and the average low is -2 °C (28 °F).
Does it rain a lot in Philadelphia in December?
On average about 111 mm (4.4 in) of precipitation falls in December; it ranks 4th of the 12 months.
Is December 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 December?
In the middle of December the day in Philadelphia lasts about 9.3 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Philadelphia in December?
The average relative humidity in December is about 85%. This is a long-term average for the whole day.
How cloudy is Philadelphia in December?
On average about 63% of the sky is covered by cloud in December. 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.