Philadelphia, PA weather in December
December in Philadelphia: chilly, with frequent rain and some snow. Highs 46°F, lows 31°F, rain or snow on about 11 days and about 3.5 in of snow.
- Normal high
- 46°F
- Normal low
- 31°F
- Wet days
- 11
- 4.0 in total
- Snowfall
- 3.5 in
- snow on the ground 3 days
How December changes from start to finish
| December 1 | December 31 | |
|---|---|---|
| Normal high | 50°F | 43°F |
| Normal low | 35°F | 28°F |
| Chance of a wet day | 34% | 36% |
| Sunrise / sunset | 7:03 am / 4:36 pm | 7:22 am / 4:45 pm |
| Daylight | 9.6 h | 9.4 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical December day
- 6 am36°Fdew point 27°F
- 9 am38°Fdew point 28°F
- Noon43°Fdew point 28°F
- 3 pm44°Fdew point 28°F
- 6 pm41°Fdew point 28°F
- 9 pm39°Fdew point 28°F
NOAA hourly normals (local standard time) from Philadelphia Intl Airport (7 mi away); average wind 10 mph; clear or few clouds in 57% of daytime hours, mostly cloudy or overcast in 39%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F1 of 31
- Hot dayshigh 90°F or more0 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow11 of 31
- Notable rainat least 0.10 in7 of 31
- Freezing nightslow 32°F or below17 of 31
- Snow on the groundsnow depth 1 in or more3 of 31
Average days per December, counted from daily records for each year 1991-2020.
Rain and snow in December
Normal precipitation is 4.0 in; a dry December brings about 2.9 in and a wet one about 5.0 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 1 an inch or more. Normal snowfall is 3.5 in, with about 1 day of an inch or more.
How December varies from year to year
- Warmest December, 1991-20202015: average high 58°F
- Coolest December1995: average high 38°F
- Wettest December2009: 8.9 in
- Driest December1998: 0.8 in
- Highest reading73°F (December 7, 1998)
- Lowest reading9°F (December 31, 2017)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
December compared with November and January
| November | December | January | |
|---|---|---|---|
| Normal high | 56°F | 46°F | 41°F |
| Normal low | 39°F | 31°F | 26°F |
| Wet days | 9 | 11 | 11 |
| Comfortable days | 5 | 1 | 1 |
| Daylight | 10.0 h | 9.4 h | 9.7 h |
Highs change by -10°F from November and -5°F into January.
Nearby alternatives in December
- Warmer: Williamsburg, VA203 mi · high 53°F · 11 wet days
- Cooler: Springfield, MA200 mi · high 41°F · 12 wet days
How Philadelphia ranks in December
- Normal high220th warmest of 378 cities; 1st of 4 in Pennsylvania
- Wet days270th driest of 378
- Comfortable days203rd most of 340
What to pack for Philadelphia in December
- A warm jacket – lows near 31°F, highs near 46°F
- A rain jacket or umbrella – rain or snow on about 11 days
- Waterproof boots – about 3.5 in of snow in a typical year
- A hat and gloves – about 17 freezing nights
Heating and cooling
December has 818 heating degree days and 0 cooling degree days (base 65°F), 14% of the year's total heating and cooling demand.
Questions
How cold is Philadelphia in December?
The normal high is 46°F and the normal low is 31°F. From 1991 to 2020 the coldest December reading was 9°F (December 31, 2017).
Does it rain a lot in Philadelphia in December?
About 11 days in December have at least 0.01 in of precipitation, and the normal total is 4.0 in. The wettest December in 1991-2020 was in 2009 (8.9 in); the driest was in 1998 (0.8 in).
Does it snow in Philadelphia in December?
Yes. Normal snowfall in December is 3.5 in, and snow covers the ground on about 3 days.
Is December a good time to visit Philadelphia?
December ranks 11th of 12 months on our comfort score for Philadelphia (36 out of 100). It has about 1 comfortable day. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and humidity and wind by hour: Philadelphia Intl Airport (USW00013739), 6.8 mi SSW of the city center, 10 ft . NOAA normals and daily records, 1991-2020.
- Frost dates: Phila Franklin Inst (USC00366886), 0.6 mi NW of the city center, 60 ft . NOAA normals and daily records, 1991-2020.
- Cloud cover: Philadelphia Ne Airport (USW00094732), 12 mi NE of the city center, 100 ft (65 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Philadelphia International Airport (724080-13739), 6.4 mi SSW of the city center, 7 ft . Hourly observations, 1991-2020.