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Contents
- The climate of Isle Royale National Park
- The best time to visit Isle Royale National Park
- The worst time to visit Isle Royale National Park
- Spring weather in Isle Royale National Park
- Summer weather in Isle Royale National Park
- Autumn weather in Isle Royale National Park
- Winter weather in Isle Royale National Park
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average rainfall
- Average rainfall days
- Average sea temperature
- Average daylight
- Average sunshine
- Average UV index
Calm evening waters at the Rock Harbor in Isle Royale National Park, Michigan, USA
The climate of Isle Royale National Park
Positioned in Michigan, the Isle Royale National Park is a place where weather fluctuates significantly throughout the year. The climate is classified as Dfb under the Köppen climate scale, indicating a humid continental arrangement with no dry season and a warm summer. The overall weather in this national park experiences variations with each passing month.
Temperatures show a wide-ranging disparity across the year, with elevated peaks from May to September, while low records are noticed from November until April. During the warmest month in July, average highest temperature measures reach 75°F (23.9°C). Observing the cooler months, January brings the lowest average temperatures, commonly dropping to 0°F (-17.8°C).
With respect to precipitation, the Isle Royale National Park receives an average of 31.6" (803mm) per annum. The highest rainfall, approximately 3.4" (86mm), occurs in the month of September. Rainfall counts stay modest in February and March, only averaging between 1.5" (38mm) and 1.9" (48mm). The count of rainfall days fluctuates from 8 days in April to 13 days in June and September.
Sea temperatures also change during the various seasons and observe a rise from 36°F (2.2°C) in the early part of the year to 55°F (12.8°C) in August. Likewise, the number of daylight hours fluctuates from 8.9 hours in January and climbs to its maximum, 16 hours in June. The park's UV index is also noteworthy, with highest levels measuring 7 in June and July, followed by a decrease to 1 by December.
Temperatures show a wide-ranging disparity across the year, with elevated peaks from May to September, while low records are noticed from November until April. During the warmest month in July, average highest temperature measures reach 75°F (23.9°C). Observing the cooler months, January brings the lowest average temperatures, commonly dropping to 0°F (-17.8°C).
With respect to precipitation, the Isle Royale National Park receives an average of 31.6" (803mm) per annum. The highest rainfall, approximately 3.4" (86mm), occurs in the month of September. Rainfall counts stay modest in February and March, only averaging between 1.5" (38mm) and 1.9" (48mm). The count of rainfall days fluctuates from 8 days in April to 13 days in June and September.
Sea temperatures also change during the various seasons and observe a rise from 36°F (2.2°C) in the early part of the year to 55°F (12.8°C) in August. Likewise, the number of daylight hours fluctuates from 8.9 hours in January and climbs to its maximum, 16 hours in June. The park's UV index is also noteworthy, with highest levels measuring 7 in June and July, followed by a decrease to 1 by December.
The best time to visit Isle Royale National Park
The appropriate time for a visit to Isle Royale National Park is often determined by the visitor's preferred activities. Typically, the months of June to September, promoting pleasant weather, invite a large number of visitors. The park experiences maximum sunshine hours from June until August, with the longest day being in June, providing 16 hours of daylight. These months also witness a moderate level of rainfall and temperatures ranging from 59°F (15°C) to 75°F (23.9°C).
The worst time to visit Isle Royale National Park
The less favorable period to visit Isle Royale National Park tends to be the colder months from December until February. During these periods, the park witnesses the lowest temperatures of the year dropping to 0°F (-17.8°C). Furthermore, days are shorter during this period with only around 8.9 hours to 10.3 hours of daylight, alongside minimum sunshine hours of 3 to 4.
Spring weather in Isle Royale National Park
The spring season in Isle Royale National Park, from March to May, is marked by an increase in temperatures and daylight hours. Temperatures during this period range from 12°F (-11.1°C) in March to 59°F (15°C) in May. Daylight hours progress from 11.9 hours in March to 15.2 hours in May. Precipitation values stay between 1.7" (43mm) and 2.7" (69mm) throughout these months.
Summer weather in Isle Royale National Park
During the summer months of June through August, Isle Royale National Park showcases peak temperatures, rising from 68°F (20°C) in June to 75°F (23.9°C) in July, before declining to 72°F (22.2°C) in August. Rainfall shows an increase, peaking at 3.3" (84mm) and 3.4" (86mm) in August and September, respectively. Daylight hours reach their highest, offering visitors up to 16 hours of daylight in June.
Autumn weather in Isle Royale National Park
Autumn in Isle Royale National Park, covering September through November, witnesses a decline in temperatures. Values descend from 63°F (17.2°C) in September to 36°F (2.2°C) in November. Rainfall sits between 3.4" (86mm) in September and 2.3" (58mm) in November. Meanwhile, daylight hours gradually dwindle from 12.6 hours in September to 9.3 hours in November.
Winter weather in Isle Royale National Park
The winter period in Isle Royale National Park, from December until February, offers the coldest conditions of the entire year with temperatures fluctuating between 0°F (-17.8°C) to 21°F (-6.1°C). Precipitation averages around 2.5" (64mm) in December and falls to 1.5" (38mm) in January. The number of daylight hours remains low and ranges from 8.9 hours in December to 10.3 hours in February.
Weather in January
January in Isle Royale National Park, Michigan, witnesses winter at its peak. The chilly weather continues from December, making it the coldest month of the year. Surprisingly, despite the cold, a moderate amount of rainfall is observed with precipitation for 10 days. Weather in January »
Weather in February
The frigid weather prevails in February, following suit from January. However, a gradual increase in temperature begins to mark the transition towards the warmer months. The weather remains cloudy for substantial periods, indicating the sustained trend of rainfall from the preceding month. Weather in February »
Weather in March
March brings in the first whispers of spring as the weather starts shifting from extreme cold. The weather shows a palpable increase from the freezing temperatures of February. Sunlight becomes more prevalent, heralding longer days and hinting at the upcoming spring. Weather in March »
Weather in April
April indicates the arrival of spring in Isle Royale National Park, Michigan. Weather conditions transform significantly from the chilling atmosphere of March. April also marks an increase in daylight hours, indicating longer, sunnier days ahead. Weather in April »
Weather in May
May ushers in the true essence of spring with its mild and comfortable climate. It offers a respite from the long, dreary winter. Following April, May continues the trend of increased daylight hours. Rainfall is expected to be slightly higher than the previous month, making the location greener. Weather in May »
Weather in June
June introduces the early signs of summer with warmer weather. From spring-like weather in May, June displays a noticeable increase in temperature. Long daylight hours and their added sunshine make this month suitable for outdoor activities. Weather in June »
Weather in July
July brings the peak of summer in Isle Royale National Park, Michigan. The increase in temperature from June makes July the warmest month of the year. There's an abundance of sunlight, making this a perfect time for sunbathing. The levels of rainfall exhibit a slight decline compared to the preceding months. Weather in July »
Weather in August
In August, the weather begins to mellow down from the peak in July. However, the summer heat still predominates, although slightly less intense than July. Rainfall shows a marginal increase, retaining moisture within the environment. Weather in August »
Weather in September
September marks the onset of autumn in Isle Royale National Park, Michigan. A noticeable temperature drop from August brings in the distinct autumn chill. Despite the decrease, the weather remains pleasantly warm during daylight hours. Weather in September »
Weather in October
October ensures the full arrival of autumn with its cool and crisp weather. The noticeable decrease in temperature from September sets the tone for the upcoming winter. Rainfall quantities remain relatively similar, contributing to the moisture in the air. Weather in October »
Weather in November
November is a prelude to winter in Isle Royale National Park, Michigan. A significant dip in temperature from October marks the gradual transition towards winter. The duration of daylight diminishes as the winter solstice approaches. Weather in November »
Weather in December
December witnesses the onset of winter, concluding the cycle of the year. Cold weather characterizes this month, increasing from the cool temperatures of November. Daylight hours are curtailed dramatically, indicating the waning of the Sun. Weather in December »
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the coldest months in Isle Royale National Park?
With average high and low temperatures of 17.6°F (-8°C) and -0.4°F (-18°C) respectively, January is Isle Royale National Park's coldest month.
How many days does it rain in Isle Royale National Park?
Throughout the year, in Isle Royale National Park, there are 125 rainfall days, and 30.55" (776mm) of precipitation is accumulated.
When is the ocean coldest in Isle Royale National Park?
January through April, with an average ocean temperature of 35.6°F (2°C), are months with the coldest seawater in Isle Royale National Park, Michigan.
What is the month with the lowest UV index in Isle Royale National Park?
The months with the lowest UV index in Isle Royale National Park are January, February, November and December, with an average maximum UV index of 1.
What is the driest month in Isle Royale National Park?
February is the month with the least rainfall in Isle Royale National Park. Rain falls for 8 days and accumulates 1.5" (38mm) of precipitation.
When is Daylight Saving Time (DST) in Isle Royale National Park?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Isle Royale National Park, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.
When are the longest days in Isle Royale National Park?
The month with the longest days in Isle Royale National Park, Michigan, is June, with an average of 16h and 0min of daylight.
When is the highest UV index in Isle Royale National Park?
The months with the highest UV index in Isle Royale National Park are June and July, with an average maximum UV index of 7.
What month is the hottest in Isle Royale National Park?
July, noted for its average high-temperature of 75.2°F (24°C) and an average low-temperature of 53.6°F (12°C), is considered the warmest month in Isle Royale National Park.
What month has the most sunshine in Isle Royale National Park?
The month with the most sunshine is July, with an average of 10h of sunshine.
What month is the ocean warmest in Isle Royale National Park?
The month with the warmest seawater in Isle Royale National Park, Michigan, is August, with an average ocean temperature of 55.4°F (13°C).
What is the rainiest month in Isle Royale National Park?
September is the month with the most rainfall in Isle Royale National Park. Rain falls for 13 days and accumulates 3.39" (86mm) of precipitation.
What are the months with the least sunshine in Isle Royale National Park?
The months with the least sunshine in Isle Royale National Park, Michigan, are November and December, with an average of 3h of sunshine.
What is the month with the shortest days in Isle Royale National Park?
The month with the shortest days is December, with an average of 8h and 30min of daylight.
Average temperature
Isle Royale National Park, MI
The warmest month (with the highest average high temperature) is July (75°F).
The month with the lowest average high temperature is January (18°F).
The month with the highest average low temperature is July (54°F).
The coldest month (with the lowest average low temperature) is January (0°F).
Average rainfall
Isle Royale National Park, MI
The wettest month (with the highest rainfall) is September (3.4").
The driest month (with the least rainfall) is February (1.5").
Average rainfall days
Isle Royale National Park, MI
- Average rainfall days in January:
10 days - Average rainfall days in February:
8 days - Average rainfall days in March:
9 days - Average rainfall days in April:
8 days - Average rainfall days in May:
10 days - Average rainfall days in June:
13 days
- Average rainfall days in July:
11 days - Average rainfall days in August:
12 days - Average rainfall days in September:
13 days - Average rainfall days in October:
11 days - Average rainfall days in November:
9 days - Average rainfall days in December:
11 days
The months with the highest number of rainy days are June and September (13 days).
The months with the least rainy days are February and April (8 days).
Average sea temperature
Isle Royale National Park, MI
The best month for swimming (with the highest average sea temperature) is August (55°F).
The coldest months (with the lowest average sea temperature) are January, February, March and April (36°F).
Average daylight / Average sunshine
Isle Royale National Park, MI
- Average daylight in January:
8h and 5min - Average daylight in February:
10h and 2min - Average daylight in March:
11h and 5min - Average daylight in April:
13h and 4min - Average daylight in May:
15h and 1min - Average daylight in June:
16h and 0min
- Average daylight in July:
15h and 4min - Average daylight in August:
14h and 1min - Average daylight in September:
12h and 4min - Average daylight in October:
10h and 5min - Average daylight in November:
9h and 2min - Average daylight in December:
8h and 3min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 30min).
The month with the most sunshine is July (Average sunshine: 10h).
The months with the least sunshine are November and December (Average sunshine: 3h).
Average UV index
Isle Royale National Park, MI
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 1).
Isle Royale National Park, Michigan, USA
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