December Weather in Greeley, United States

Last updated: June 24, 2025

In December, the average temperature in Greeley, United States hovers around -1°C (30°F), with temperatures ranging from a frigid -24°C (-12°F) to a mild 20°C (68°F). Expect 42 mm (1.6 in) of precipitation spread over 4 days, and don’t forget to prepare for the high average humidity of 79%!

December Temperature in Greeley

In December in Greeley, the average temperature is -1°C (30°F). Maximum temperatures can reach 20°C (68°F), while minimums can drop as low as -24°C (-12°F). Be sure to pack for a wide range of weather conditions when traveling during this time.

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

The chart illustrates December temperature patterns in Greeley, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Greeley, December typically has an average temperature of -1°C (30°F), with highs reaching up to 20°C (68°F) and lows dropping to around -24°C (-12°F).

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

December Precipitation in Greeley

In Greeley in December, the precipitation amount is 42 mm (1.6 in) spread over a period of 4 days.

December Precipitation Trends in Greeley

The chart displays monthly precipitation patterns in Greeley, 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 Greeley, December typically receives around 42 mm (1.6 inches) of precipitation spread over approximately 4 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 Greeley

In Greeley in December, humidity is 79%. With an average temperature of -1°C (30°F), this humidity feels like a biting chill in the air, making outdoor activities uncomfortable and requiring extra layers to stay warm while exploring.

December Average Humidity in Greeley

This chart illustrates the average monthly humidity levels in Greeley, 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 Greeley is approximately 79%, 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 Greeley

In Greeley 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 Greeley, you can check the information here.

Maximum UV Index Levels in Greeley for December

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

Data source: Greeley 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 Greeley Compares to Other Months

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

This table compares monthly weather conditions in Greeley, 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 (25°F)	24 mm (0.9 inches)	73%	moderate
February Weather	-4°C (25°F)	20 mm (0.8 inches)	81%	moderate
March Weather	4°C (39°F)	84 mm (3.3 inches)	69%	high
April Weather	9°C (48°F)	61 mm (2.4 inches)	71%	very high
May Weather	15°C (60°F)	144 mm (5.7 inches)	80%	very high
June Weather	23°C (74°F)	89 mm (3.5 inches)	83%	extreme
July Weather	25°C (77°F)	77 mm (3.0 inches)	84%	very high
August Weather	23°C (73°F)	91 mm (3.6 inches)	84%	very high
September Weather	20°C (68°F)	57 mm (2.3 inches)	77%	very high
October Weather	10°C (50°F)	85 mm (3.3 inches)	72%	high
November Weather	4°C (39°F)	22 mm (0.9 inches)	80%	moderate
December Weather	-1°C (30°F)	42 mm (1.6 inches)	79%	moderate