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December Weather in Idaho Falls, United States

Last updated: June 24, 2025

In December, the average temperature in Idaho Falls, United States is a chilly -4°C (26°F), with minimums plummeting to -18°C (0°F) and maximums rising to 12°C (54°F). Expect 41 mm (1.6 in) of precipitation spread over 10 days, accompanied by a high average humidity of 91%. Prepare for a frosty yet intriguing atmosphere!

December Temperature in Idaho Falls

In December in Idaho Falls, the average temperature is -4°C (26°F). Maximums can reach 12°C (54°F), while minimums can drop as low as -18°C (0°F). Travelers should be prepared for chilly conditions and dress in layers to stay comfortable during their visit.

December Weather in Idaho Falls: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Idaho Falls, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Idaho Falls, December typically has an average temperature of -4°C (26°F), with highs reaching up to 12°C (54°F) and lows dropping to around -18°C (0°F).
JanFebMarAprMayJunJulAugSepOctNovDec242737455464737161453526
Data source: Temperature data for Idaho Falls 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 Idaho Falls

In Idaho Falls in December, the precipitation amount is 41 mm (1.6 in) spread over 10 days.

December Precipitation Trends in Idaho Falls

The chart displays monthly precipitation patterns in Idaho Falls, 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 Idaho Falls, December typically receives around 41 mm (1.6 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec404843555831111627393241
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Idaho Falls

In Idaho Falls in December, humidity is 91%. With an average temperature of -4°C (26°F), this humidity feels like you are walking through a thick, icy fog, making it incredibly challenging for traveling as the cold air clings to your skin, and each breath brings a sharp chill.

December Average Humidity in Idaho Falls

This chart illustrates the average monthly humidity levels in Idaho Falls, 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 Idaho Falls is approximately 91%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec95%95%90%81%71%64%59%49%52%69%86%91%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Idaho Falls

In Idaho Falls 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 Idaho Falls, you can check the information here.

Maximum UV Index Levels in Idaho Falls for December

The chart shows the monthly maximum UV Index (UVI) for Idaho Falls 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 Idaho Falls typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3578101111109643
Data source: Idaho Falls 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 Idaho Falls Compares to Other Months

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

This table compares monthly weather conditions in Idaho Falls, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-5°C (24°F)40 mm (1.6 inches)95%moderate
February Weather-3°C (27°F)48 mm (1.9 inches)95%moderate
March Weather3°C (37°F)43 mm (1.7 inches)90%high
April Weather7°C (45°F)55 mm (2.2 inches)81%very high
May Weather12°C (54°F)58 mm (2.3 inches)71%very high
June Weather18°C (65°F)31 mm (1.2 inches)64%extreme
July Weather23°C (74°F)11 mm (0.4 inches)59%extreme
August Weather21°C (71°F)16 mm (0.6 inches)49%very high
September Weather16°C (61°F)26 mm (1.0 inches)52%very high
October Weather7°C (45°F)39 mm (1.5 inches)69%high
November Weather2°C (36°F)32 mm (1.3 inches)86%moderate
December Weather-4°C (26°F)41 mm (1.6 inches)91%moderate

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