December Weather in Greeley, United States

Last updated: June 24, 2025

In Greeley, United States, the average temperature in December hovers around 0°C (33°F). This chilly month sees minimum temperatures plunging to -18°C (0°F), while the highs can reach a surprisingly warm 22°C (72°F). Expect a total precipitation of 10 mm (0.4 in) spread across 2 days, with an average humidity level of 77%.

December Temperature in Greeley

In December in Greeley, the average temperature is 0°C (33°F). The maximum can reach 22°C (72°F) and the minimum can be as low as -18°C (0°F). Be prepared for a wide range of temperatures when traveling to Greeley in December.

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 0°C (33°F), with highs reaching up to 22°C (72°F) and lows dropping to around -18°C (0°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 10 mm (0.4 in) over a period of 2 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 10 mm (0.4 inches) of precipitation spread over approximately 2 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 77%. With an average temperature of 0°C (33°F), this humidity feels like a chill that seeps into your bones, making outdoor exploration less enjoyable and prompting you to seek warm, cozy spots for a reprieve from the dampness.

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 77%, 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	-1°C (31°F)	11 mm (0.4 inches)	72%	moderate
February Weather	-1°C (30°F)	13 mm (0.5 inches)	76%	moderate
March Weather	5°C (42°F)	44 mm (1.7 inches)	61%	high
April Weather	9°C (49°F)	35 mm (1.4 inches)	60%	very high
May Weather	14°C (58°F)	95 mm (3.8 inches)	74%	very high
June Weather	21°C (71°F)	34 mm (1.3 inches)	82%	extreme
July Weather	25°C (77°F)	30 mm (1.2 inches)	82%	extreme
August Weather	23°C (74°F)	32 mm (1.3 inches)	84%	very high
September Weather	20°C (68°F)	15 mm (0.6 inches)	75%	very high
October Weather	10°C (49°F)	24 mm (0.9 inches)	73%	high
November Weather	5°C (41°F)	15 mm (0.6 inches)	74%	moderate
December Weather	0°C (33°F)	10 mm (0.4 inches)	77%	moderate