December Weather in Summit, United States

Last updated: June 24, 2025

In Summit, United States, the average temperature in December hovers around 12°C (53°F). Expect a cozy range with minimums dipping to -2°C (29°F) and highs reaching 27°C (80°F). Rainfall is modest, with 23 mm (0.9 in) spread over 3 days, and the atmosphere tends to be quite humid, averaging around 81%.

December Temperature in Summit

In December in Summit, the average temperature is 12°C (53°F). The maximum can reach 27°C (80°F), while the minimum can drop as low as -2°C (29°F). This variety in temperature makes it a great time for travelers to enjoy a mix of outdoor activities and cozy indoor experiences.

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

The chart illustrates December temperature patterns in Summit, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Summit, December typically has an average temperature of 12°C (53°F), with highs reaching up to 27°C (80°F) and lows dropping to around -2°C (29°F).

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

December Precipitation in Summit

In Summit in December, the precipitation amount is 23 mm (0.9 in) over the course of 3 days.

December Precipitation Trends in Summit

The chart displays monthly precipitation patterns in Summit, 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 Summit, December typically receives around 23 mm (0.9 inches) of precipitation spread over approximately 3 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 Summit

In Summit in December, humidity is 81%. With an average temperature of 12°C (53°F), this humidity feels like a chilly dampness enveloping you, making outdoor activities uncomfortable and requiring layers to stay warm while you explore.

December Average Humidity in Summit

This chart illustrates the average monthly humidity levels in Summit, 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 Summit is approximately 81%, 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 Summit

In Summit in December, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Summit.

Maximum UV Index Levels in Summit for December

The chart shows the monthly maximum UV Index (UVI) for Summit 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 Summit typically reaches 5, which falls under the moderate exposure category.

Data source: Summit 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 Summit Compares to Other Months

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

This table compares monthly weather conditions in Summit, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	11°C (52°F)	19 mm (0.7 inches)	74%	moderate
February Weather	12°C (55°F)	29 mm (1.2 inches)	71%	high
March Weather	16°C (61°F)	14 mm (0.5 inches)	60%	very high
April Weather	21°C (70°F)	3 mm (0.1 inches)	43%	extreme
May Weather	25°C (77°F)	3 mm (0.1 inches)	32%	extreme
June Weather	30°C (87°F)	7 mm (0.3 inches)	28%	extreme
July Weather	30°C (87°F)	50 mm (2.0 inches)	38%	extreme
August Weather	30°C (86°F)	42 mm (1.7 inches)	60%	extreme
September Weather	28°C (82°F)	31 mm (1.2 inches)	72%	extreme
October Weather	22°C (72°F)	10 mm (0.4 inches)	66%	very high
November Weather	17°C (63°F)	13 mm (0.5 inches)	74%	high
December Weather	12°C (53°F)	23 mm (0.9 inches)	81%	moderate