January Weather in Boston, United States

Last updated: June 24, 2025

In January, the average temperature in Boston, United States is a cool 12°C (54°F). Visitors should prepare for a range of temperatures, with a minimum of -6°C (21°F) and a maximum of 27°C (82°F). Expect some rain, as the area receives about 72 mm (2.8 in) of precipitation over approximately 6 days. Be ready for a humid atmosphere, with an average humidity level of 85%.

January Temperature in Boston

In January in Boston, the average temperature is 12°C (54°F). The maximum can reach 27°C (82°F), and the minimum can be as low as -6°C (21°F). This makes it essential for travelers to pack for a range of temperatures to ensure comfort during their stay.

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

The chart illustrates January temperature patterns in Boston, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Boston, January typically has an average temperature of 12°C (54°F), with highs reaching up to 27°C (82°F) and lows dropping to around -6°C (21°F).

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

January Precipitation in Boston

In Boston in January, the total precipitation amount is 72 mm (2.8 in) over the course of 6 days.

January Precipitation Trends in Boston

The chart displays monthly precipitation patterns in Boston, 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 Boston, January typically receives around 72 mm (2.8 inches) of precipitation spread over approximately 6 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in Boston

In Boston in January, humidity is 85%. With an average temperature of 12°C (54°F), this humidity feels like a heavy blanket wrapping around you, making traveling not only uncomfortable but also exhausting as the damp air clings to your skin and slows your movements.

January Average Humidity in Boston

This chart illustrates the average monthly humidity levels in Boston, 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 Boston is approximately 85%, 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 Boston

In Boston in January, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Boston.

Maximum UV Index Levels in Boston for January

The chart shows the monthly maximum UV Index (UVI) for Boston 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 Boston typically reaches 5, which falls under the moderate exposure category.

Data source: Boston 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 Boston Compares to Other Months

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

This table compares monthly weather conditions in Boston, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	12°C (54°F)	72 mm (2.8 inches)	85%	moderate
February Weather	15°C (60°F)	96 mm (3.8 inches)	82%	very high
March Weather	17°C (64°F)	52 mm (2.1 inches)	80%	very high
April Weather	20°C (69°F)	80 mm (3.1 inches)	76%	very high
May Weather	25°C (76°F)	74 mm (2.9 inches)	73%	extreme
June Weather	27°C (80°F)	157 mm (6.2 inches)	74%	extreme
July Weather	27°C (81°F)	148 mm (5.8 inches)	80%	extreme
August Weather	27°C (82°F)	137 mm (5.4 inches)	79%	extreme
September Weather	26°C (80°F)	110 mm (4.3 inches)	83%	very high
October Weather	23°C (74°F)	73 mm (2.9 inches)	77%	very high
November Weather	16°C (61°F)	50 mm (2.0 inches)	84%	high
December Weather	13°C (56°F)	117 mm (4.6 inches)	88%	moderate