January Weather in Plymouth, United States

Last updated: June 24, 2025

In January, the average temperature in Plymouth, United States hovers around 7°C (45°F). However, be prepared for temperature fluctuations, as the minimum can drop to a chilly -18°C (-1°F), while the maximum can reach a pleasant 25°C (77°F). During this month, expect approximately 90 mm (3.5 in) of precipitation spread over 8 days, coupled with a high average humidity of 84%.

January Temperature in Plymouth

In January in Plymouth, the average temperature is 7°C (45°F). The maximum can reach 25°C (77°F), while the minimum can drop as low as -18°C (-1°F). It's advisable to pack a variety of clothing to accommodate the fluctuating temperatures when traveling during this time.

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 7°C (45°F), with highs reaching up to 25°C (77°F) and lows dropping to around -18°C (-1°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 90 mm (3.5 in) spread over 8 days, indicating a relatively wet period for the region.

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 90 mm (3.5 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 7°C (45°F), this humidity feels like a damp chill that seeps into your bones, making travel uncomfortable and necessitating extra layers to stay warm while exploring the sights.

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 reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Plymouth for better planning.

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 4, 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	7°C (45°F)	90 mm (3.5 inches)	84%	moderate
February Weather	10°C (50°F)	95 mm (3.7 inches)	81%	high
March Weather	12°C (53°F)	64 mm (2.5 inches)	80%	very high
April Weather	17°C (62°F)	100 mm (3.9 inches)	80%	very high
May Weather	21°C (70°F)	114 mm (4.5 inches)	81%	extreme
June Weather	25°C (76°F)	149 mm (5.9 inches)	82%	very high
July Weather	27°C (80°F)	141 mm (5.5 inches)	83%	extreme
August Weather	26°C (79°F)	170 mm (6.7 inches)	82%	very high
September Weather	24°C (75°F)	125 mm (4.9 inches)	80%	very high
October Weather	19°C (67°F)	75 mm (2.9 inches)	79%	very high
November Weather	12°C (54°F)	96 mm (3.8 inches)	83%	moderate
December Weather	9°C (49°F)	108 mm (4.2 inches)	84%	moderate