nomadseason

December Weather in Philadelphia, United States

Last updated: June 24, 2025

In December, the average temperature in Philadelphia, United States hovers around 8°C (46°F), with a minimum dip of -7°C (19°F) and a maximum rise to 22°C (72°F). Expect 137 mm (5.4 in) of precipitation spread over 11 days, contributing to an average humidity of 88%. Stay prepared for a mix of cool temperatures and wet weather!

December Temperature in Philadelphia

In December in Philadelphia, the average temperature is 8°C (46°F), with maximums reaching up to 22°C (72°F) and minimums dipping as low as -7°C (19°F). This varied climate makes it essential for travelers to pack layers to comfortably navigate both warm and chilly moments during their visit.

December Weather in Philadelphia: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Philadelphia, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Philadelphia, December typically has an average temperature of 8°C (46°F), with highs reaching up to 22°C (72°F) and lows dropping to around -7°C (19°F).
JanFebMarAprMayJunJulAugSepOctNovDec424753607076807874645046
Data source: Temperature data for Philadelphia generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Philadelphia

In Philadelphia in December, the total precipitation amount reaches 137 mm (5.4 in) over a span of 11 days.

December Precipitation Trends in Philadelphia

The chart displays monthly precipitation patterns in Philadelphia, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Philadelphia, December typically receives around 137 mm (5.4 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec1001761601411131071111199211879137
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

December Humidity in Philadelphia

In Philadelphia in December, humidity is 88%. With an average temperature of 8°C (46°F), this humidity feels like a damp chill that seeps into your bones, making outdoor exploration feel much more uncomfortable than the temperature alone would suggest.

December Average Humidity in Philadelphia

This chart illustrates the average monthly humidity levels in Philadelphia, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Philadelphia is approximately 88%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec86%86%86%82%85%85%83%76%76%80%88%88%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Philadelphia

In Philadelphia in December, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Philadelphia, you can check the information here.

Maximum UV Index Levels in Philadelphia for December

The chart shows the monthly maximum UV Index (UVI) for Philadelphia in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In December, the maximum UV index in Philadelphia typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec36810111111109753
Data source: Philadelphia December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How December Weather in Philadelphia Compares to Other Months

Weather in Philadelphia varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Philadelphia, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Philadelphia, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather6°C (42°F)99 mm (3.9 inches)86%moderate
February Weather8°C (47°F)176 mm (6.9 inches)86%high
March Weather12°C (53°F)160 mm (6.3 inches)86%very high
April Weather15°C (60°F)141 mm (5.5 inches)82%very high
May Weather21°C (70°F)113 mm (4.4 inches)85%extreme
June Weather24°C (76°F)107 mm (4.2 inches)85%extreme
July Weather26°C (80°F)111 mm (4.4 inches)83%extreme
August Weather26°C (78°F)119 mm (4.7 inches)76%very high
September Weather24°C (75°F)92 mm (3.6 inches)76%very high
October Weather18°C (65°F)118 mm (4.6 inches)80%high
November Weather10°C (50°F)79 mm (3.1 inches)88%moderate
December Weather8°C (46°F)137 mm (5.4 inches)88%moderate

Compare Philadelphia's Climate with Cities Worldwide