January Weather in Belfast, United States

Last updated: June 24, 2025

In Belfast, United States, the average temperature in January typically hovers around -4°C (24°F). Expect temperatures to range from a chilly -26°C (-14°F) at their lowest to a milder 12°C (54°F) at their peak. During this month, 93 mm (3.7 in) of precipitation is spread over 9 days, contributing to an average humidity level of 88%. Prepare for brisk conditions and damp air as you explore this winter wonderland!

January Temperature in Belfast

In January in Belfast, the average temperature is -4°C (24°F). Maximum temperatures can reach 12°C (54°F), while minimums can dip as low as -26°C (-14°F). Travelers should prepare for a wide range of temperatures and pack accordingly for chilly conditions.

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

The chart illustrates January temperature patterns in Belfast, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Belfast, January typically has an average temperature of -4°C (24°F), with highs reaching up to 12°C (54°F) and lows dropping to around -26°C (-14°F).

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

January Precipitation in Belfast

In Belfast in January, the precipitation amount is 93 mm (3.7 in) over the course of 9 days.

January Precipitation Trends in Belfast

The chart displays monthly precipitation patterns in Belfast, 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 Belfast, January typically receives around 93 mm (3.7 inches) of precipitation spread over approximately 9 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 Belfast

In Belfast in January, humidity is 88%. With an average temperature of -4°C (24°F), this humidity feels like an icy blanket enveloping you, making every breath feel crisp and biting, which can be quite challenging for traveling.

January Average Humidity in Belfast

This chart illustrates the average monthly humidity levels in Belfast, 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 Belfast 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 Belfast

In Belfast in January, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Belfast, you can visit Hourly UV Index in Belfast.

Maximum UV Index Levels in Belfast for January

The chart shows the monthly maximum UV Index (UVI) for Belfast 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 Belfast typically reaches 2, which falls under the low exposure category.

Data source: Belfast 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 Belfast Compares to Other Months

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

This table compares monthly weather conditions in Belfast, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (24°F)	93 mm (3.7 inches)	88%	low
February Weather	-4°C (26°F)	88 mm (3.5 inches)	88%	moderate
March Weather	0°C (32°F)	72 mm (2.9 inches)	85%	moderate
April Weather	6°C (43°F)	131 mm (5.2 inches)	81%	high
May Weather	11°C (53°F)	90 mm (3.6 inches)	76%	very high
June Weather	17°C (63°F)	76 mm (3.0 inches)	74%	very high
July Weather	20°C (68°F)	91 mm (3.6 inches)	74%	very high
August Weather	20°C (68°F)	75 mm (3.0 inches)	74%	very high
September Weather	16°C (61°F)	77 mm (3.0 inches)	77%	high
October Weather	11°C (51°F)	130 mm (5.1 inches)	82%	moderate
November Weather	3°C (38°F)	121 mm (4.8 inches)	85%	moderate
December Weather	-2°C (28°F)	129 mm (5.1 inches)	84%	low