World Resorts USA Grand Marais Weather

Grand Marais weather in September

Weather in Grand Marais: September

Average day temperature: 62.0°F
Average night temperature: 54.4°F
Sea water temperature: 58.8°F
Number of sunny days: 13 days
Day length: 11.7 - 13.4 hours
Number of rainy days: 1 day
Precipitation totals: 0.7 in.

Air temperature in September, °F

Show year:
2026
2025
2024

The highest day temperature during September of 2026 was 71°F. At the same time the lowest night temperature was 47°F. Daily and nightly averages during September were 61.0°F and 55.5°F.

Sea water temperature in Grand Marais in September, °F

Show year:
2026
2025
2024

The average sea water temperature in September of 2026 was 56.4°F. The highest and lowest sea temperatures during the month were 63.0°F and 45.7°F.

Sunny, partly cloudy and cloudy days

Mostly all days in September are sunny but cloudy days are also possible.

Precipitation total in September, in.

Precipitation total value in Grand Marais in September is 0.7 in. Other months of the year show relatively similar values.

Wind speed in September, mph

The average wind speed value in September is 7.4 mph It makes September one of the least windy months of the year.

Average sunny hours

This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in September is: 7.4.

Best time for vacation in Grand Marais

Sunniest months:
August 14 days
September 13 days
July 12 days
Warmest months:
August 67.8 °F
July 66.6 °F
September 62.0 °F
Warmest sea temp:
August 59.3 °F
September 58.7 °F
October 52.8 °F
Coldest months:
January 18.7 °F
February 19.7 °F
December 24.9 °F
Rainiest months:
August 3 days
April 2 days
July 2 days
Windiest months:
November 10.0 mph
December 9.9 mph
January 9.6 mph

Grand Marais on a weather map

Grand Marais
+55°F
NW 6 mph
Feels like: +55°F
Precip.: 19%
Places in USA:
Name
°F
+57°F
+66°F
+77°F
+72°F
+73°F
+84°F
+61°F
+59°F
+73°F
+57°F
+72°F
+84°F
+91°F
+64°F
24 Hours Forecast
Grand Marais
Local time: 12:17
September 28, monday
1500
57°F
NW
5 mph
1800
57°F
SW
5 mph
2100
55°F
SW
6 mph
September 29, tuesday
0000
55°F
SW
7 mph
0300
55°F
SW
4 mph
0600
55°F
W
4 mph
0900
57°F
NW
2 mph
1200
59°F
N
7 mph
Units of measurement: °C / °F