December Weather in Grafton, United States

Last updated: June 24, 2025

In December, the average temperature in Grafton, United States hovers around -9°C (16°F), with extremes ranging from a chilling -33°C (-27°F) to a mild 8°C (47°F). During this time, expect about 30 mm (1.2 in) of precipitation over 7 days, coupled with a high average humidity of 91%. Bundle up and prepare for a winter wonderland!

December Temperature in Grafton

In December in Grafton, the average temperature is -9°C (16°F). The maximum can reach 8°C (47°F), while the minimum can drop as low as -33°C (-27°F). Be sure to bundle up and prepare for a range of cold temperatures when traveling to Grafton during this time of year.

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

The chart illustrates December temperature patterns in Grafton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grafton, December typically has an average temperature of -9°C (16°F), with highs reaching up to 8°C (47°F) and lows dropping to around -33°C (-27°F).

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

December Precipitation in Grafton

In Grafton in December, the total precipitation amount is 30 mm (1.2 in) over a span of 7 days.

December Precipitation Trends in Grafton

The chart displays monthly precipitation patterns in Grafton, 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 Grafton, December typically receives around 30 mm (1.2 inches) of precipitation spread over approximately 7 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 Grafton

In Grafton in December humidity is 91%. With an average temperature of -9°C (16°F), this humidity feels like a heavy veil wrapping around you, making outdoor exploration quite challenging as you navigate through the chilly air that seems to cling to your skin.

December Average Humidity in Grafton

This chart illustrates the average monthly humidity levels in Grafton, 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 Grafton is approximately 91%, 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 Grafton

In Grafton in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Grafton, you can visit Hourly UV Index in Grafton.

Maximum UV Index Levels in Grafton for December

The chart shows the monthly maximum UV Index (UVI) for Grafton 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 Grafton typically reaches 2, which falls under the low exposure category.

Data source: Grafton 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 Grafton Compares to Other Months

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

This table compares monthly weather conditions in Grafton, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-13°C (9°F)	17 mm (0.6 inches)	92%	low
February Weather	-14°C (7°F)	18 mm (0.7 inches)	90%	moderate
March Weather	-4°C (25°F)	22 mm (0.9 inches)	88%	moderate
April Weather	3°C (38°F)	27 mm (1.1 inches)	81%	high
May Weather	13°C (55°F)	48 mm (1.9 inches)	74%	very high
June Weather	20°C (68°F)	64 mm (2.5 inches)	72%	very high
July Weather	22°C (72°F)	54 mm (2.1 inches)	74%	very high
August Weather	20°C (68°F)	63 mm (2.5 inches)	76%	very high
September Weather	15°C (59°F)	82 mm (3.2 inches)	73%	high
October Weather	6°C (43°F)	79 mm (3.1 inches)	76%	moderate
November Weather	-3°C (26°F)	26 mm (1.0 inches)	86%	moderate
December Weather	-9°C (16°F)	30 mm (1.2 inches)	91%	low