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December Weather in New Castle, United States

Last updated: June 24, 2025

In December, the average temperature in New Castle, United States hovers around 4°C (39°F), with minimums dipping to -16°C (4°F) and maximums reaching up to 19°C (67°F). Be prepared for about 98 mm (3.9 in) of precipitation spread over 8 days, and with an average humidity of 86%, it’s sure to be a brisk and damp month!

December Temperature in New Castle

In December in New Castle, the average temperature is 4°C (39°F). Maximum can reach 19°C (67°F) and minimum can be as low as -16°C (4°F). Be sure to pack layers to stay comfortable while exploring the diverse weather conditions.

December Weather in New Castle: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in New Castle, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In New Castle, December typically has an average temperature of 4°C (39°F), with highs reaching up to 19°C (67°F) and lows dropping to around -16°C (4°F).
JanFebMarAprMayJunJulAugSepOctNovDec354045546370757368584439
Data source: Temperature data for New Castle 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 New Castle

In New Castle in December, the total precipitation amount is 98 mm (3.9 in), occurring over 8 days.

December Precipitation Trends in New Castle

The chart displays monthly precipitation patterns in New Castle, 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 New Castle, December typically receives around 98 mm (3.9 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec7411182120147117781091141147598
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in New Castle

In New Castle in December humidity is 86%. With an average temperature of 4°C (39°F), this humidity feels like a chilly mist enveloping you, making it essential to bundle up while exploring, as each breath comes with a damp chill that can be quite refreshing yet starkly invigorating for travelers.

December Average Humidity in New Castle

This chart illustrates the average monthly humidity levels in New Castle, 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 New Castle is approximately 86%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%87%86%84%83%83%79%66%68%78%89%86%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in New Castle

In New Castle 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 New Castle, you can check the information here.

Maximum UV Index Levels in New Castle for December

The chart shows the monthly maximum UV Index (UVI) for New Castle 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 New Castle typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec36810101111109753
Data source: New Castle 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 New Castle Compares to Other Months

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

This table compares monthly weather conditions in New Castle, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather2°C (35°F)73 mm (2.9 inches)87%moderate
February Weather5°C (41°F)111 mm (4.4 inches)87%high
March Weather7°C (46°F)82 mm (3.2 inches)86%very high
April Weather12°C (55°F)120 mm (4.7 inches)84%very high
May Weather17°C (64°F)147 mm (5.8 inches)83%very high
June Weather21°C (70°F)117 mm (4.6 inches)83%extreme
July Weather24°C (75°F)78 mm (3.1 inches)79%extreme
August Weather23°C (73°F)109 mm (4.3 inches)66%very high
September Weather20°C (68°F)114 mm (4.5 inches)68%very high
October Weather15°C (58°F)114 mm (4.5 inches)78%high
November Weather6°C (44°F)75 mm (3.0 inches)89%moderate
December Weather4°C (39°F)98 mm (3.9 inches)86%moderate

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