August weather forecast
Grand Portage, MN

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Weather in August

August in Grand Portage maintains the summer enthusiasm with sustained warmth and a slightly increased relative humidity. The earlier rise in temperature begins to show a downward trend moving towards autumn. Long daylight hours continue to favor outdoor activities and beach outings. The Wind speed fluctuates minimally, ensuring a comfortable atmosphere. Soothing sea temperatures still allow for a dip in the water marking summer's end.

Temperature

The yearly peak temperatures occur in July and August, averaging a high-temperature of 70°F (21.1°C).

Humidity

In August, the average relative humidity in Grand Portage is 77%.

Rainfall

In Grand Portage, in August, it is raining for 11.4 days, with typically 1.61" (41mm) of accumulated precipitation. Throughout the year, there are 115 rainfall days, and 18.19" (462mm) of precipitation is accumulated.

Snowfall

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

Ocean temperature

August is the month with the warmest seawater, with an average ocean temperature of 59°F (15°C).
Note: For the majority, swimming in 59°F (15°C) does not offer a pleasant experience. Below 69.8°F (21°C), the difficulty in controlling breathing escalates.

Daylight

In Grand Portage, Minnesota, the average length of the day in August is 14h and 14min.
On the first day of August, sunrise is at 5:36 am and sunset at 8:33 pm. On the last day of the month, sunrise is at 6:16 am and sunset at 7:41 pm CDT.

Sunshine

The average sunshine in August is 9.4h.

UV index

In August, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the ordinary person.
Note: In August, an average UV index of 4 transforms into the following instructions:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the warmest months in Grand Portage?

In Grand Portage, Minnesota, the warmest months are July and August, registering an average high-temperature of 70°F (21.1°C).

What is the average August temperature in Grand Portage?

The average high-temperature and low-temperature during August are 70°F (21.1°C) and 54.3°F (12.4°C) respectively.

What is the average humidity in August in Grand Portage?

In Grand Portage, the average relative humidity in August is 77%.

How many days does it rain in August in Grand Portage?

In Grand Portage, in August, it is raining for 11.4 days, with typically 1.61" (41mm) of accumulated precipitation.

When it does not snow in Grand Portage?

June through September are months without snowfall in Grand Portage.

When is the ocean warmest in Grand Portage?

August is the month with the warmest seawater, with an average ocean temperature of 59°F (15°C).

What is the ocean temperature in August in Grand Portage?

In Grand Portage, Minnesota, the average seawater temperature in August is 59°F (15°C). For most, swimming in 59°F (15°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).

How many hours of daylight does Grand Portage have in August?

The average day length in August in Grand Portage is 14h and 14min.

When is the sunrise / sunset in August in Grand Portage?

On the first day of August, sunrise is at 5:36 am and sunset at 8:33 pm. On the last day of the month, sunrise is at 6:16 am and sunset at 7:41 pm CDT.

How long on average sun shines in August in Grand Portage?

In August, the average sunshine duration in Grand Portage, Minnesota, is 9.4h.

What is the UV index intensity in August in Grand Portage?

The average daily maximum UV index in August in Grand Portage is 4. A UV Index value of 3 to 5 symbolizes a moderate health threat from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Grand Portage, MN

Average temperature in August - Grand Portage, MN
  • Average high temperature in August: 70°F

The warmest months (with the highest average high temperature) are July and August (70°F).
The month with the lowest average high temperature is January (16.2°F).

  • Average low temperature in August: 54.3°F

The month with the highest average low temperature is August (54.3°F).
The coldest month (with the lowest average low temperature) is January (3.7°F).

Average pressure in August
Grand Portage, MN

Average pressure in August - Grand Portage, MN
  • Average pressure in August: 29.91"Hg

The month with the highest atmospheric pressure is March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in August
Grand Portage, MN

Average wind speed in August - Grand Portage, MN
  • Average wind speed in August: 6.6mph

The windiest month (with the highest average wind speed) is December (9.2mph).
The calmest month (with the lowest average wind speed) is June (6.2mph).

Average humidity in August
Grand Portage, MN

Average humidity in August - Grand Portage, MN
  • Average humidity in August: 77%

The months with the highest relative humidity are January and February (90%).
The month with the lowest relative humidity is May (70%).

Average rainfall in August
Grand Portage, MN

Average rainfall in August - Grand Portage, MN
  • Average rainfall in August: 1.61"

The wettest months (with the highest rainfall) are May and October (1.77").
The driest months (with the least rainfall) are January and February (1.06").

Average rainfall days in August
Grand Portage, MN

Average rainfall days in August - Grand Portage, MN
  • Average rainfall days in August: 11.4 days

The month with the highest number of rainy days is July (12.9 days).
The month with the least rainy days is February (4.2 days).

Average snowfall in August
Grand Portage, MN

Average snowfall in August - Grand Portage, MN
  • Average snowfall in August: 0"

The month with the highest snowfall is January (7.76").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in August
Grand Portage, MN

Average snowfall days in August - Grand Portage, MN
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (21.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average sea temperature in August
Grand Portage, MN

Average sea temperature in August - Grand Portage, MN
  • Average sea temperature in August: 59°F

The best month for swimming (with the highest average sea temperature) is August (59°F).
The coldest months (with the lowest average sea temperature) are January, February, March and April (36°F).

Average daylight in August /
Average sunshine in August
Grand Portage, MN

Average daylight in August / Average sunshine in August - Grand Portage, MN
  • Average daylight in August: 14h and 1min

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).

  • Average sunshine in August: 9h and 2min

The month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).

Average sunshine days in August
Grand Portage, MN

Average sunshine days in August - Grand Portage, MN
  • Average sunshine days in August: 18 days

The month with the most sunshine days is September (18.1 days).
The month with the least sunshine days is March (9.8 days).

Average UV index in August
Grand Portage, MN

Average UV index in August - Grand Portage, MN
  • Average UV index in August: 4

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

Average cloud cover in August
Grand Portage, MN

Average cloud cover in August - Grand Portage, MN
  • Average cloud cover in August: 34

The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is July (Cloud cover 33).

Average visibility in August
Grand Portage, MN

Average visibility in August - Grand Portage, MN
  • Average visibility in August: 6mi

The months with the highest visibility are May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March, April and December (5mi).

Grand Portage, Minnesota, USA

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