April Weather in Southwest Harbor, United States

Last updated: June 24, 2025

In Southwest Harbor, United States, the average temperature in April hovers around 5°C (41°F). Expect chilly days, with a minimum dipping to -3°C (27°F) and a maximum reaching 13°C (55°F). This month brings 143 mm (5.6 in) of precipitation over approximately 13 days, contributing to a high average humidity of 81%. Prepare for a damp and cool atmosphere!

April Temperature in Southwest Harbor

In April in Southwest Harbor, the average temperature is 5°C (41°F), with maximums reaching 13°C (55°F) and minimums dropping as low as -3°C (27°F). Be sure to prepare for a range of temperatures when planning your trip!

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

The chart illustrates April 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, April typically has an average temperature of 5°C (41°F), with highs reaching up to 13°C (55°F) and lows dropping to around -3°C (27°F).

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

April Precipitation in Southwest Harbor

In Southwest Harbor in April, the precipitation amount is 143 mm (5.6 in) over a span of 13 days.

April Precipitation Trends in Southwest Harbor

The chart displays monthly precipitation patterns in Southwest Harbor, with values for each month alongside April’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how April’s conditions compare to those of other months. In Southwest Harbor, April typically receives around 143 mm (5.6 inches) of precipitation spread over approximately 13 days.

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

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Millimeters (mm) Inches (in)

April Humidity in Southwest Harbor

In Southwest Harbor in April, humidity is 81%. With an average temperature of 5°C (41°F), this humidity feels like a chilly dampness that clings to your skin, making outdoor exploration uncomfortable and requiring warm, waterproof clothing to stay comfortable while traveling.

April Average Humidity in Southwest Harbor

This chart illustrates the average monthly humidity levels in Southwest Harbor, with April’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In April, average humidity in Southwest Harbor is approximately 81%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for April generated using information from the Copernicus Climate Change Service.

April UV Index in Southwest Harbor

In Southwest Harbor in April, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Southwest Harbor.

Maximum UV Index Levels in Southwest Harbor for April

The chart shows the monthly maximum UV Index (UVI) for Southwest Harbor in April, 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 April, the maximum UV index in Southwest Harbor typically reaches 7, which falls under the high exposure category.

Data source: Southwest Harbor April 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 April 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 April’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 April’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