Climate and monthly weather forecast
Grand Isle, ME

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Weather in January

January, the same as December, in Grand Isle, Maine, is another subzero cold winter month, with an average temperature varying between 18°F (-7.8°C) and 2.8°F (-16.2°C). Grand Isle witnesses the coldest weather in January, with temperatures averaging a high of 18°F (-7.8°C) and a low of 2.8°F (-16.2°C). Weather in January »

Weather in February

February, the last month of the winter in Grand Isle, is another freezing cold month, with an average temperature ranging between max 20.3°F (-6.5°C) and min 3.6°F (-15.8°C). With the transition into February, Grand Isle notes an average high-temperature of a still freezing cold 20.3°F (-6.5°C), closely resembling January. Weather in February »

Weather in March

March, the first month of the spring in Grand Isle, is also a subzero cold month, with an average temperature ranging between max 27.7°F (-2.4°C) and min 11.7°F (-11.3°C). The commencement of March sees a minor shift in the average high-temperature, moving from 20.3°F (-6.5°C) in February to a still freezing cold 27.7°F (-2.4°C). Weather in March »

Weather in April

April is a wintry spring month in Grand Isle, Maine, with temperature in the range of an average low of 26.1°F (-3.3°C) and an average high of 40.8°F (4.9°C). With the onset of April, Grand Isle experiences a temperature shift, with the average high-temperature moving from a subzero cold 27.7°F (-2.4°C) in March to a cold 40.8°F (4.9°C). Weather in April »

Weather in May

The last month of the spring, May, is a refreshing month in Grand Isle, Maine, with an average temperature fluctuating between 39.6°F (4.2°C) and 58.8°F (14.9°C). The arrival of May brings a distinct temperature shift, with the average high-temperature escalating from an icy 40.8°F (4.9°C) in April to a refreshing 58.8°F (14.9°C). Weather in May »

Weather in June

The first month of the summer, June, is a refreshing month in Grand Isle, Maine, with an average temperature ranging between min 47.3°F (8.5°C) and max 67.5°F (19.7°C). June brings a slight increase in the average high-temperature, progressing from a moderate 58.8°F (14.9°C) in May to a still refreshing 67.5°F (19.7°C). Weather in June »

Weather in July

July in Grand Isle, Maine, is a warm summer month, with an average temperature fluctuating between 74.3°F (23.5°C) and 53.6°F (12°C). In Grand Isle, temperatures reach their average annual highs in July, measuring 74.3°F (23.5°C) and a minimum average of 53.6°F (12°C). Weather in July »

Weather in August

August, the last month of the summer in Grand Isle, is also an agreeable month, with an average temperature fluctuating between 72.3°F (22.4°C) and 52.7°F (11.5°C). The average high-temperature in August, at a pleasant 72.3°F (22.4°C), reveals a modest deviation from July's 74.3°F (23.5°C). Weather in August »

Weather in September

September, the first month of the autumn in Grand Isle, is still a comfortable month, with an average temperature ranging between min 45.1°F (7.3°C) and max 63.5°F (17.5°C). The arrival of September signals a subtle shift in temperature, down from an agreeable 72.3°F (22.4°C) in August to an enjoyable 63.5°F (17.5°C). Weather in September »

Weather in October

October, like September, is another chilly autumn month in Grand Isle, Maine, with an average temperature ranging between min 36°F (2.2°C) and max 49.5°F (9.7°C). The start of October involves a temperature drop, moving from an enjoyable 63.5°F (17.5°C) in September to a frosty 49.5°F (9.7°C). Weather in October »

Weather in November

The last month of the autumn, November, is another cold month in Grand Isle, Maine, with an average temperature varying between 25.2°F (-3.8°C) and 36.5°F (2.5°C). A moderate decline in the average high-temperature is seen during November, decreasing from a chilly 49.5°F (9.7°C) in October to a wintry 36.5°F (2.5°C). Weather in November »

Weather in December

December, the first month of the winter in Grand Isle, is still a freezing cold month, with an average temperature varying between 23.9°F (-4.5°C) and 12.2°F (-11°C). The onset of December results in a decrease in the average high-temperature, receding from a cold 36.5°F (2.5°C) in November to a freezing cold 23.9°F (-4.5°C). Weather in December »

Frequently asked questions

What are the coldest months?

Grand Isle's coldest weather arrives in January, when temperatures average a high of 18°F (-7.8°C) and a low of 2.8°F (-16.2°C).

How many days does it rain?

Throughout the year, there are 140.8 rainfall days, and 30.12" (765mm) of precipitation is accumulated.

When does it snow?

Months with snowfall in Grand Isle are January through May, October through December.

What is the snowiest month?

The month with the most snowfall is January, when snow falls for 21.3 days and typically aggregates up to 14.92" (379mm) of snow.

How many days does it snow?

Throughout the year, there are 107.8 snowfall days, and 71.34" (1812mm) of snow is accumulated.

What is the month with the lowest UV index?

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 1.

What is the driest month?

February is the month with the least rainfall. Rain falls for 4.3 days and accumulates 1.97" (50mm) of precipitation.

What is the month with the least sunshine in Grand Isle?

February has the least sunshine of the year, with an average of 2.1h of sunshine.

What is the most humid month?

With an average relative humidity of 94%, March is the most humid month.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, 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.

What is the wettest month?

The month with the most rainfall is April, when the rain falls for 14 days and typically aggregates up to 2.95" (75mm) of precipitation.

What is the least humid month?

The least humid month is May, with an average relative humidity of 76%.

When it does not snow?

In Grand Isle, snow does not fall in June through September.

When are the longest days?

With an average of 15h and 54min of daylight, June has the longest days of the year.

What is the month with the highest UV index in Grand Isle?

June and July, with an average maximum UV index of 5, are months with the highest UV index.

What time of the year is the hottest?

In Grand Isle, temperatures reach their average annual highs in July, measuring 74.3°F (23.5°C) and a minimum average of 53.6°F (12°C).

What month has the most sunshine?

With an average of 9.5h of sunshine, August has the most sunshine of the year.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 8h and 30min of daylight.

Average temperature
Grand Isle, ME

Average temperature - Grand Isle, ME

The warmest month (with the highest average high temperature) is July (74.3°F).
The month with the lowest average high temperature is January (18°F).

The month with the highest average low temperature is July (53.6°F).
The coldest month (with the lowest average low temperature) is January (2.8°F).

Average pressure
Grand Isle, ME

Average pressure - Grand Isle, ME

The months with the highest atmospheric pressure are March, September and November (30.01"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).

Average wind speed
Grand Isle, ME

Average wind speed - Grand Isle, ME

The windiest months (with the highest average wind speed) are January and February (8.2mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

Average humidity
Grand Isle, ME

Average humidity - Grand Isle, ME

The month with the highest relative humidity is March (94%).
The month with the lowest relative humidity is May (76%).

Average rainfall
Grand Isle, ME

Average rainfall - Grand Isle, ME

The wettest month (with the highest rainfall) is April (2.95").
The driest month (with the least rainfall) is February (1.97").

Average rainfall days
Grand Isle, ME

Average rainfall days - Grand Isle, ME

The month with the highest number of rainy days is July (17.1 days).
The months with the least rainy days are January and February (4.3 days).

Average snowfall
Grand Isle, ME

Average snowfall - Grand Isle, ME

The month with the highest snowfall is January (14.92").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days
Grand Isle, ME

Average snowfall days - Grand Isle, ME

The month with the highest number of snowfall days is January (21.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight / Average sunshine
Grand Isle, ME

Average daylight / Average sunshine - Grand Isle, ME

The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).

The month with the most sunshine is August (Average sunshine: 9h and 30min).
The month with the least sunshine is February (Average sunshine: 2h and 6min).

Average sunshine days
Grand Isle, ME

Average sunshine days - Grand Isle, ME

The month with the most sunshine days is September (14.5 days).
The month with the least sunshine days is April (7.9 days).

Average UV index
Grand Isle, ME

Average UV index - Grand Isle, ME

The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 1).

Average visibility
Grand Isle, ME

Average visibility - Grand Isle, ME

The months with the highest visibility are May, June, July, August, September, October and November (5mi).
The months with the lowest visibility are January, February, March, April and December (4mi).

Grand Isle, Maine, USA

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