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December Weather in Greencastle, United States

Last updated: June 24, 2025

In Greencastle, United States, the average temperature in December hovers around 3°C (38°F). Expect a minimum plunge to -12°C (10°F) and a maximum rise to 19°C (66°F). During this time, precipitation averages 95 mm (3.7 in) spread over 9 days, contributing to an average humidity of 85%. Keep these factors in mind as you plan your visit!

December Temperature in Greencastle

In December in Greencastle, the average temperature is 3°C (38°F), with maximums reaching up to 19°C (66°F) and minimums dropping as low as -12°C (10°F). It's essential to prepare for a wide range of temperatures when planning your travels to Greencastle during this time.

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

The chart illustrates December temperature patterns in Greencastle, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Greencastle, December typically has an average temperature of 3°C (38°F), with highs reaching up to 19°C (66°F) and lows dropping to around -12°C (10°F).
JanFebMarAprMayJunJulAugSepOctNovDec343744546473787670594438
Data source: Temperature data for Greencastle 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 Greencastle

In Greencastle in December, the precipitation amount is 95 mm (3.7 in) over the course of 9 days.

December Precipitation Trends in Greencastle

The chart displays monthly precipitation patterns in Greencastle, 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 Greencastle, December typically receives around 95 mm (3.7 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec62948810111890124871101058195
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Greencastle

In Greencastle in December, humidity is 85%. With an average temperature of 3°C (38°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities uncomfortable and travel less enjoyable as you contend with the heavy, cold air surrounding you.

December Average Humidity in Greencastle

This chart illustrates the average monthly humidity levels in Greencastle, 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 Greencastle is approximately 85%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec86%86%86%84%78%79%70%59%68%80%87%85%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Greencastle

In Greencastle 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 Greencastle, you can check the information here.

Maximum UV Index Levels in Greencastle for December

The chart shows the monthly maximum UV Index (UVI) for Greencastle 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 Greencastle typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec357910101098743
Data source: Greencastle 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 Greencastle Compares to Other Months

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

This table compares monthly weather conditions in Greencastle, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (34°F)62 mm (2.4 inches)86%moderate
February Weather3°C (38°F)94 mm (3.7 inches)86%moderate
March Weather6°C (44°F)88 mm (3.5 inches)86%high
April Weather12°C (54°F)101 mm (4.0 inches)84%very high
May Weather18°C (64°F)118 mm (4.7 inches)78%very high
June Weather23°C (73°F)90 mm (3.5 inches)79%very high
July Weather26°C (79°F)124 mm (4.9 inches)70%very high
August Weather24°C (76°F)87 mm (3.4 inches)59%very high
September Weather21°C (70°F)110 mm (4.3 inches)68%very high
October Weather15°C (60°F)104 mm (4.1 inches)80%high
November Weather7°C (45°F)81 mm (3.2 inches)86%moderate
December Weather3°C (38°F)95 mm (3.7 inches)85%moderate

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