January Weather in Groton, United States

Last updated: June 24, 2025

In Groton, United States, the average temperature in January hovers around -10°C (15°F). However, be prepared for extremes: the minimum can plummet to -38°C (-36°F), while the maximum can reach up to 7°C (44°F). Expect about 18 mm (0.7 in) of precipitation spread over 5 days, and brace yourself for an average humidity level of 81%.

January Temperature in Groton

In January in Groton, the average temperature is -10°C (15°F). Maximum temperatures can reach 7°C (44°F), while the minimum can drop as low as -38°C (-36°F). Travelers should be prepared for extremely cold conditions and dress warmly when visiting this location during this time.

January Weather in Groton: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Groton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Groton, January typically has an average temperature of -10°C (15°F), with highs reaching up to 7°C (44°F) and lows dropping to around -38°C (-36°F).

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

January Precipitation in Groton

In Groton in January, the precipitation amount is 18 mm (0.7 in) spread over a duration of 5 days.

January Precipitation Trends in Groton

The chart displays monthly precipitation patterns in Groton, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Groton, January typically receives around 18 mm (0.7 inches) of precipitation spread over approximately 5 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

January Humidity in Groton

In Groton in January humidity is 81%. With an average temperature of -10°C (15°F), this humidity feels like a biting frost that clings to your skin, making travel uncomfortable and chilly, as the cold air sharpens with every breath.

January Average Humidity in Groton

This chart illustrates the average monthly humidity levels in Groton, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Groton is approximately 81%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Groton

In Groton in January, 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 Groton, you can check the information here.

Maximum UV Index Levels in Groton for January

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

Data source: Groton January 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 January Weather in Groton Compares to Other Months

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

This table compares monthly weather conditions in Groton, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-10°C (15°F)	18 mm (0.7 inches)	81%	moderate
February Weather	-10°C (14°F)	16 mm (0.6 inches)	85%	moderate
March Weather	-1°C (31°F)	35 mm (1.4 inches)	76%	moderate
April Weather	5°C (41°F)	47 mm (1.9 inches)	79%	high
May Weather	14°C (57°F)	64 mm (2.5 inches)	76%	very high
June Weather	22°C (71°F)	65 mm (2.6 inches)	81%	very high
July Weather	24°C (75°F)	76 mm (3.0 inches)	82%	very high
August Weather	21°C (71°F)	108 mm (4.2 inches)	82%	very high
September Weather	17°C (63°F)	88 mm (3.5 inches)	77%	high
October Weather	8°C (46°F)	76 mm (3.0 inches)	76%	moderate
November Weather	0°C (33°F)	17 mm (0.7 inches)	84%	moderate
December Weather	-5°C (23°F)	33 mm (1.3 inches)	81%	low