January Weather in Plymouth, United States

Last updated: June 24, 2025

In Plymouth, United States, the average temperature in January hovers around -2°C (29°F). Expect chilly extremes with minimums plummeting to -21°C (-6°F) and a rare maximum of 18°C (65°F). Precipitation is notable, with 73 mm (2.9 in) falling over 8 days, contributing to an overall average humidity of 84%.

January Temperature in Plymouth

In January in Plymouth, the average temperature is -2°C (29°F). Maximum temperatures can reach 18°C (65°F), while minimums can drop as low as -21°C (-6°F). Be prepared for a wide range of temperatures when traveling during this month.

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

The chart illustrates January temperature patterns in Plymouth, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Plymouth, January typically has an average temperature of -2°C (29°F), with highs reaching up to 18°C (65°F) and lows dropping to around -21°C (-6°F).

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

January Precipitation in Plymouth

In Plymouth in January, the precipitation amount is 73 mm (2.9 in) over a span of 8 days.

January Precipitation Trends in Plymouth

The chart displays monthly precipitation patterns in Plymouth, 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 Plymouth, January typically receives around 73 mm (2.9 inches) of precipitation spread over approximately 8 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 Plymouth

In Plymouth in January, humidity is 84%. With an average temperature of -2°C (29°F), this humidity feels like an icy blanket that clings to your skin, making it difficult to stay warm and comfortable while traveling.

January Average Humidity in Plymouth

This chart illustrates the average monthly humidity levels in Plymouth, 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 Plymouth is approximately 84%, 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 Plymouth

In Plymouth 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 Plymouth, you can check the information here.

Maximum UV Index Levels in Plymouth for January

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

Data source: Plymouth 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 Plymouth Compares to Other Months

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

This table compares monthly weather conditions in Plymouth, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-2°C (29°F)	73 mm (2.9 inches)	84%	moderate
February Weather	0°C (32°F)	93 mm (3.7 inches)	82%	moderate
March Weather	3°C (38°F)	91 mm (3.6 inches)	81%	high
April Weather	9°C (48°F)	136 mm (5.3 inches)	78%	very high
May Weather	15°C (59°F)	120 mm (4.7 inches)	69%	very high
June Weather	20°C (69°F)	103 mm (4.1 inches)	69%	very high
July Weather	23°C (74°F)	162 mm (6.4 inches)	62%	very high
August Weather	22°C (73°F)	107 mm (4.2 inches)	65%	very high
September Weather	19°C (66°F)	122 mm (4.8 inches)	68%	very high
October Weather	13°C (56°F)	152 mm (6.0 inches)	74%	high
November Weather	5°C (42°F)	95 mm (3.7 inches)	82%	moderate
December Weather	1°C (33°F)	123 mm (4.9 inches)	80%	low