December Weather in Alta, United States

Last updated: June 24, 2025

In December, the average temperature in Alta, United States hovers around 4°C (39°F), with extremes ranging from a chilly -7°C (20°F) to a pleasantly warm 21°C (71°F). Expect a precipitation of 225 mm (8.8 in) spread over about 12 days, contributing to a rather high average humidity of 83%.

December Temperature in Alta

In December in Alta, the average temperature is 4°C (39°F). Maximum temperatures can reach 21°C (71°F), while minimum temperatures can drop as low as -7°C (20°F). Travelers should be prepared for a wide range of temperatures, ensuring they pack layers for varying weather conditions.

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

The chart illustrates December temperature patterns in Alta, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Alta, December typically has an average temperature of 4°C (39°F), with highs reaching up to 21°C (71°F) and lows dropping to around -7°C (20°F).

Data source: Temperature data for Alta generated using information from the Copernicus Climate Change Service.

December Precipitation in Alta

In Alta in December, the precipitation amount is 225 mm (8.8 in) falling over the course of 12 days.

December Precipitation Trends in Alta

The chart displays monthly precipitation patterns in Alta, 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 Alta, December typically receives around 225 mm (8.8 inches) of precipitation spread over approximately 12 days.

Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

December Humidity in Alta

In Alta in December, humidity is 83%. With an average temperature of 4°C (39°F), this humidity feels like a damp chill that penetrates your clothing, making outdoor activities feel brisk and uncomfortable for traveling.

December Average Humidity in Alta

This chart illustrates the average monthly humidity levels in Alta, 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 Alta is approximately 83%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Alta

In Alta 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 Alta, you can check the information here.

Maximum UV Index Levels in Alta for December

The chart shows the monthly maximum UV Index (UVI) for Alta 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 Alta typically reaches 3, which falls under the moderate exposure category.

Data source: Alta 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 Alta Compares to Other Months

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

This table compares monthly weather conditions in Alta, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	4°C (39°F)	289 mm (11.4 inches)	84%	moderate
February Weather	4°C (40°F)	295 mm (11.6 inches)	84%	moderate
March Weather	5°C (42°F)	284 mm (11.2 inches)	83%	very high
April Weather	9°C (49°F)	140 mm (5.5 inches)	81%	very high
May Weather	13°C (56°F)	90 mm (3.5 inches)	74%	extreme
June Weather	19°C (66°F)	20 mm (0.8 inches)	64%	extreme
July Weather	23°C (74°F)	3 mm (0.1 inches)	44%	extreme
August Weather	22°C (72°F)	6 mm (0.2 inches)	36%	very high
September Weather	18°C (65°F)	25 mm (1.0 inches)	44%	very high
October Weather	12°C (55°F)	77 mm (3.0 inches)	65%	high
November Weather	8°C (46°F)	163 mm (6.4 inches)	84%	moderate
December Weather	4°C (39°F)	225 mm (8.8 inches)	83%	moderate