January Weather in Boston, Ireland

Last updated: August 23, 2025

In January, the average temperature in Boston, Ireland is a cool 6°C (44°F), with temperatures ranging from a brisk -4°C (25°F) to a mild 14°C (58°F). Expect 86 mm (3.4 in) of precipitation spread over 13 days, making it a fairly wet month. With an average humidity of 88%, be prepared for a damp and chilly atmosphere!

January Temperature in Boston

In January in Boston, the average temperature is 6°C (44°F), with maximums reaching 14°C (58°F) and minimums dipping as low as -4°C (25°F). It's essential to pack layers to stay comfortable while exploring the area during this time.

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 6°C (44°F), with highs reaching up to 14°C (58°F) and lows dropping to around -4°C (25°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 precipitation amount is 86 mm (3.4 in) over the course of 13 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 86 mm (3.4 inches) of precipitation spread over approximately 13 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 Boston

In Boston in January humidity is 88%. With an average temperature of 6°C (44°F), this humidity feels like a damp chill that seeps into your bones, making outdoor adventures less inviting and requiring warm, layered clothing to stay comfortable while exploring.

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 88%, 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 is 1, which corresponds to a low Exposure Category. This means you have a time to burn of 45 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 1, which falls under the low 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	6°C (44°F)	86 mm (3.4 inches)	88%	low
February Weather	7°C (44°F)	138 mm (5.4 inches)	88%	low
March Weather	7°C (45°F)	112 mm (4.4 inches)	87%	moderate
April Weather	9°C (49°F)	61 mm (2.4 inches)	86%	moderate
May Weather	12°C (53°F)	68 mm (2.7 inches)	83%	high
June Weather	14°C (57°F)	76 mm (3.0 inches)	83%	very high
July Weather	16°C (60°F)	84 mm (3.3 inches)	85%	very high
August Weather	15°C (59°F)	133 mm (5.2 inches)	85%	high
September Weather	13°C (56°F)	102 mm (4.0 inches)	88%	moderate
October Weather	11°C (52°F)	121 mm (4.8 inches)	91%	moderate
November Weather	8°C (47°F)	105 mm (4.1 inches)	92%	low
December Weather	7°C (45°F)	131 mm (5.2 inches)	89%	low