World Resorts USA Mackinac Island Weather

Mackinac Island Sea Temperature in September

Average sea water temperature in September:
+62.7°F
Minimum sea water temperature in September: 68.9°F
Maximum sea water temperature in September: 55.9°F

Daily 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.

Monthly sea water temperature in Mackinac Island, °F

Which USA resorts have warmest sea in September?

Place name September 2025 September 2024
Key West 86.9°F 87.4°F
Islamorada 86.7°F 87.3°F
Key Largo 86.6°F 87.1°F
Fort Lauderdale 86.4°F 86.4°F
Everglades 86.2°F 87.0°F
Miami Beach 86.1°F 86.3°F
Naples 86.1°F 87.2°F
Marco Island 86.0°F 87.2°F
South Padre Island 86.0°F 85.8°F
Corpus Christi 85.8°F 84.7°F
Miami 85.8°F 86.0°F
Cape Coral 85.2°F 86.5°F
Houston 84.9°F 83.4°F
Siesta Key 84.9°F 86.8°F
Sarasota 84.8°F 86.7°F
Cocoa Beach 84.6°F 85.2°F
Tampa 84.3°F 86.0°F
New Orleans 84.3°F 82.9°F
Mobile 84.0°F 83.5°F
Clearwater Beach 84.0°F 86.2°F

Best time for vacation in Mackinac Island

Sunniest months:
July 14 days
August 14 days
September 12 days
Warmest months:
August 69.4 °F
July 69.3 °F
September 62.9 °F
Warmest sea temp:
August 67.3 °F
July 65.1 °F
September 62.7 °F
Coldest months:
February 22.9 °F
January 24.1 °F
March 31.1 °F
Rainiest months:
August 3 days
May 2 days
July 2 days
Windiest months:
November 13.5 mph
December 12.9 mph
April 11.7 mph

Mackinac Island on a weather map

Mackinac Island
+19°F
N 22 mph
Feels like: +3°F
Precip.: 0%
Places in USA:
Name
°F
+30°F
+77°F
+77°F
+45°F
+55°F
+70°F
+77°F
+70°F
+25°F
+57°F
+48°F
+63°F
+63°F
+46°F
+5°F
24 Hours Forecast
Mackinac Island
Local time: 23:59
December 05, friday
0000
19°F
N
22 mph
0300
21°F
N
22 mph
0600
25°F
NE
24 mph
0900
28°F
NE
22 mph
1200
28°F
NE
19 mph
1500
30°F
NE
16 mph
1800
32°F
NE
16 mph
2100
32°F
NE
16 mph
Units of measurement: °C / °F