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December Weather in Thornton, United States

Last updated: June 24, 2025

In December, the average temperature in Thornton, United States hovers around 12°C (54°F). Expect a minimum of -2°C (28°F) and a peak of 28°C (83°F). Rainfall averages 91 mm (3.6 in) over about 9 days, while humidity remains high at 87%. Prepare for a mix of conditions!

December Temperature in Thornton

In December in Thornton, the average temperature is 12°C (54°F), with maximums reaching up to 28°C (83°F) and minimums dropping as low as -2°C (28°F). Be prepared for a wide range of temperatures when traveling to Thornton during this time.

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

The chart illustrates December temperature patterns in Thornton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Thornton, December typically has an average temperature of 12°C (54°F), with highs reaching up to 28°C (83°F) and lows dropping to around -2°C (28°F).
JanFebMarAprMayJunJulAugSepOctNovDec505262677582868681705954
Data source: Temperature data for Thornton 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 Thornton

In Thornton in December, the precipitation amount is 91 mm (3.6 in) spread over 9 days.

December Precipitation Trends in Thornton

The chart displays monthly precipitation patterns in Thornton, 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 Thornton, December typically receives around 91 mm (3.6 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec7810297116168755984981096791
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Thornton

In Thornton in December humidity is 87%. With an average temperature of 12°C (54°F), this humidity feels like a damp embrace, making it quite uncomfortable for traveling, as the air feels heavy and can quickly sap your energy as you explore the sights.

December Average Humidity in Thornton

This chart illustrates the average monthly humidity levels in Thornton, 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 Thornton is approximately 87%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec80%80%78%79%81%77%71%67%69%73%82%87%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Thornton

In Thornton in December, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Thornton for better planning.

Maximum UV Index Levels in Thornton for December

The chart shows the monthly maximum UV Index (UVI) for Thornton 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 Thornton typically reaches 4, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec478111111121110864
Data source: Thornton 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 Thornton Compares to Other Months

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

This table compares monthly weather conditions in Thornton, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather10°C (50°F)78 mm (3.1 inches)79%moderate
February Weather11°C (52°F)102 mm (4.0 inches)80%high
March Weather17°C (63°F)97 mm (3.8 inches)78%very high
April Weather19°C (67°F)116 mm (4.6 inches)79%extreme
May Weather24°C (76°F)168 mm (6.6 inches)81%extreme
June Weather28°C (82°F)75 mm (3.0 inches)77%extreme
July Weather30°C (86°F)59 mm (2.3 inches)71%extreme
August Weather30°C (87°F)84 mm (3.3 inches)67%extreme
September Weather27°C (81°F)98 mm (3.9 inches)69%very high
October Weather21°C (71°F)109 mm (4.3 inches)73%very high
November Weather15°C (59°F)67 mm (2.6 inches)82%high
December Weather12°C (54°F)91 mm (3.6 inches)87%moderate

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