World Resorts USA Mackinac Island Weather

Mackinac Island sea water temperature

Current sea water temperature:
+70.5°F
Minimum sea water temperature in August: 73.2°F
Maximum sea water temperature in August: 59.9°F
Average sea water temperature in August: 67.4°F

Sea water temperature for the last 10 days:

August 13 70.5°F August 8 69.4°F
August 12 70.2°F August 7 69.3°F
August 11 69.4°F August 6 68.4°F
August 10 69.8°F August 5 68.9°F
August 9 70.0°F August 4 68.5°F

When is the warmest sea in Mackinac Island?

Based on the data about daily sea water temperature for the last three years the warmest sea in Mackinac Island was noticed in August, July and September.

Monthly Sea Temperatures in Mackinac Island, °F

Sea water temperature in August, °F

Show year:
2025
2024
2023

The average sea water temperature in August of 2025 was 69.4°F. The highest and lowest sea temperatures during the month were 72.3°F and 65.3°F.

Sea water temperature in July, °F

Show year:
2026
2025
2024

The average sea water temperature in July of 2026 was 66.8°F. The highest and lowest sea temperatures during the month were 70.9°F and 62.2°F.

Sea water temperature in September, °F

Show year:
2025
2024
2023

The average sea water temperature in September of 2025 was 61.9°F. The highest and lowest sea temperatures during the month were 67.1°F and 59.4°F.

Best time for vacation in Mackinac Island

Sunniest months:
July 16 days
August 14 days
June 12 days
Warmest months:
August 69.4 °F
July 69.4 °F
September 62.9 °F
Warmest sea temp:
August 67.3 °F
July 65.3 °F
September 62.7 °F
Coldest months:
February 23.1 °F
January 23.4 °F
December 30.7 °F
Rainiest months:
August 3 days
April 2 days
July 2 days
Windiest months:
November 13.5 mph
December 13.2 mph
April 11.6 mph

Mackinac Island on a weather map

Mackinac Island
+64°F
SE 5 mph
Feels like: +64°F
Precip.: 12%
Places in USA:
Name
°F
+68°F
+77°F
+79°F
+82°F
+68°F
+79°F
+73°F
+79°F
+72°F
+68°F
+57°F
+68°F
+79°F
+79°F
+70°F
24 Hours Forecast
Mackinac Island
Local time: 03:13
August 14, friday
0600
63°F
S
6 mph
0900
64°F
S
4 mph
1200
70°F
SW
5 mph
1500
73°F
W
3 mph
1800
73°F
SW
3 mph
2100
70°F
SW
7 mph
August 15, saturday
0000
64°F
S
8 mph
0300
63°F
W
4 mph
Units of measurement: °C / °F