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December Weather in Harrisburg, United States

Last updated: June 24, 2025

In December, the average temperature in Harrisburg, United States hovers around 5°C (41°F). Expect a chilly minimum of -7°C (20°F), and a pleasant maximum of 17°C (64°F). Rainfall is common, with an average precipitation of 195 mm (7.7 in) spread over 17 days, coupled with a high average humidity of 87%. Prepare for a cool, damp month!

December Temperature in Harrisburg

In December in Harrisburg, the average temperature is 5°C (41°F). Maximums can reach 17°C (64°F), while minimums can dip to as low as -7°C (20°F). Pack accordingly to enjoy your travels, bringing layers to stay comfortable in varying temperatures.

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

The chart illustrates December temperature patterns in Harrisburg, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Harrisburg, December typically has an average temperature of 5°C (41°F), with highs reaching up to 17°C (64°F) and lows dropping to around -7°C (20°F).
JanFebMarAprMayJunJulAugSepOctNovDec414145505662686963534641
Data source: Temperature data for Harrisburg generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Harrisburg

In Harrisburg in December, the total precipitation amount is 195 mm (7.7 in) recorded over a span of 17 days.

December Precipitation Trends in Harrisburg

The chart displays monthly precipitation patterns in Harrisburg, 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 Harrisburg, December typically receives around 195 mm (7.7 inches) of precipitation spread over approximately 17 days.
JanFebMarAprMayJunJulAugSepOctNovDec1601921401256448367191143195
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Harrisburg

In Harrisburg in December humidity is 87%. With an average temperature of 5°C (41°F), this humidity feels like a heavy, damp blanket enveloping you, making every step seem laborious and the chill more biting, which can be quite challenging for traveling.

December Average Humidity in Harrisburg

This chart illustrates the average monthly humidity levels in Harrisburg, 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 Harrisburg is approximately 87%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%84%85%83%83%84%82%74%71%81%87%87%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Harrisburg

In Harrisburg in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Harrisburg, you can visit Hourly UV Index in Harrisburg.

Maximum UV Index Levels in Harrisburg for December

The chart shows the monthly maximum UV Index (UVI) for Harrisburg 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 Harrisburg typically reaches 2, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec246710101098532
Data source: Harrisburg 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 Harrisburg Compares to Other Months

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

This table compares monthly weather conditions in Harrisburg, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (42°F)160 mm (6.3 inches)85%low
February Weather5°C (41°F)192 mm (7.5 inches)84%moderate
March Weather7°C (45°F)140 mm (5.5 inches)85%high
April Weather10°C (50°F)125 mm (4.9 inches)83%high
May Weather13°C (56°F)64 mm (2.5 inches)83%very high
June Weather17°C (62°F)48 mm (1.9 inches)83%very high
July Weather20°C (68°F)2 mm (0.1 inches)82%very high
August Weather20°C (69°F)6 mm (0.2 inches)74%very high
September Weather17°C (63°F)71 mm (2.8 inches)71%very high
October Weather11°C (53°F)91 mm (3.6 inches)81%moderate
November Weather8°C (46°F)143 mm (5.6 inches)87%moderate
December Weather5°C (41°F)195 mm (7.7 inches)87%low

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