January Weather in Southwest Harbor, United States

Last updated: June 24, 2025

In January, the average temperature in Southwest Harbor, United States hovers around -1°C (30°F). Expect chilly conditions, with minimum temperatures plummeting to -16°C (3°F), while the mercury can rise as high as 11°C (52°F). This month also brings a notable precipitation amount of 113 mm (4.4 in) over approximately 10 days, contributing to an average humidity level of 88%. Prepare for a brisk and damp experience!

January Temperature in Southwest Harbor

In January in Southwest Harbor, the average temperature is -1°C (30°F), with maximums reaching up to 11°C (52°F) and minimums dropping as low as -16°C (3°F). Travelers should be prepared for cold weather and varying temperatures during this time.

January Weather in Southwest Harbor: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Southwest Harbor, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Southwest Harbor, January typically has an average temperature of -1°C (30°F), with highs reaching up to 11°C (52°F) and lows dropping to around -16°C (3°F).

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

January Precipitation in Southwest Harbor

In Southwest Harbor in January, the total precipitation amount is 113 mm (4.4 in) over a span of 10 days.

January Precipitation Trends in Southwest Harbor

The chart displays monthly precipitation patterns in Southwest Harbor, 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 Southwest Harbor, January typically receives around 113 mm (4.4 inches) of precipitation spread over approximately 10 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 Southwest Harbor

In Southwest Harbor in January humidity is 88%. With an average temperature of -1°C (30°F), this humidity feels like a biting chill that penetrates through your layers, making travel uncomfortable as every gust of wind becomes a sharp reminder of the cold and damp air surrounding you.

January Average Humidity in Southwest Harbor

This chart illustrates the average monthly humidity levels in Southwest Harbor, 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 Southwest Harbor 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 Southwest Harbor

In Southwest Harbor 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 Southwest Harbor, you can visit Hourly UV Index in Southwest Harbor.

Maximum UV Index Levels in Southwest Harbor for January

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

Data source: Southwest Harbor 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 Southwest Harbor Compares to Other Months

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

This table compares monthly weather conditions in Southwest Harbor, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-1°C (30°F)	113 mm (4.4 inches)	88%	low
February Weather	-1°C (31°F)	107 mm (4.2 inches)	88%	moderate
March Weather	1°C (34°F)	83 mm (3.3 inches)	85%	moderate
April Weather	5°C (41°F)	143 mm (5.6 inches)	81%	high
May Weather	8°C (48°F)	105 mm (4.1 inches)	76%	very high
June Weather	12°C (54°F)	95 mm (3.7 inches)	74%	very high
July Weather	15°C (59°F)	82 mm (3.2 inches)	74%	very high
August Weather	16°C (62°F)	87 mm (3.4 inches)	74%	very high
September Weather	15°C (59°F)	105 mm (4.2 inches)	77%	high
October Weather	12°C (54°F)	119 mm (4.7 inches)	82%	moderate
November Weather	6°C (44°F)	139 mm (5.5 inches)	85%	moderate
December Weather	1°C (35°F)	154 mm (6.1 inches)	84%	low