December Weather in Harvard, United States

Last updated: June 24, 2025

In December, the average temperature in Harvard, United States hovers around 0°C (33°F). Expect a chilly minimum of -20°C (-3°F), while the thermostat can soar to a comfortable 22°C (71°F). During this month, the area experiences about 41 mm (1.6 in) of precipitation spread over 4 days, with an average humidity level of 79%. Stay prepared for a mix of cold and mild weather this time of year!

December Temperature in Harvard

In December in Harvard, the average temperature is 0°C (33°F). Maximum temperatures can reach 22°C (71°F), while minimums can drop as low as -20°C (-3°F). Be prepared for a wide range of temperatures when traveling to Harvard during this month.

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

The chart illustrates December temperature patterns in Harvard, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Harvard, December typically has an average temperature of 0°C (33°F), with highs reaching up to 22°C (71°F) and lows dropping to around -20°C (-3°F).

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

December Precipitation in Harvard

In Harvard in December, the precipitation amount is 41 mm (1.6 in) over the course of 4 days.

December Precipitation Trends in Harvard

The chart displays monthly precipitation patterns in Harvard, 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 Harvard, December typically receives around 41 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.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

December Humidity in Harvard

In Harvard in December humidity is 79%. With an average temperature of 0°C (33°F), this humidity feels like a biting chill that cuts through your clothes, making traveling quite uncomfortable as the dampness clings to your skin and saps your energy.

December Average Humidity in Harvard

This chart illustrates the average monthly humidity levels in Harvard, 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 Harvard 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 Harvard

In Harvard 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 Harvard, you can check the information here.

Maximum UV Index Levels in Harvard for December

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

Data source: Harvard 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 Harvard Compares to Other Months

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

This table compares monthly weather conditions in Harvard, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-3°C (27°F)	29 mm (1.2 inches)	73%	moderate
February Weather	-3°C (27°F)	22 mm (0.9 inches)	81%	moderate
March Weather	5°C (42°F)	89 mm (3.5 inches)	69%	high
April Weather	10°C (51°F)	49 mm (1.9 inches)	71%	very high
May Weather	17°C (62°F)	172 mm (6.8 inches)	80%	very high
June Weather	24°C (76°F)	91 mm (3.6 inches)	83%	extreme
July Weather	26°C (78°F)	68 mm (2.7 inches)	84%	extreme
August Weather	24°C (75°F)	84 mm (3.3 inches)	84%	very high
September Weather	21°C (70°F)	67 mm (2.6 inches)	77%	very high
October Weather	11°C (53°F)	84 mm (3.3 inches)	72%	high
November Weather	5°C (41°F)	22 mm (0.9 inches)	80%	moderate
December Weather	0°C (33°F)	41 mm (1.6 inches)	79%	moderate