An amount below 100 means Dayton, Ohio is cheaper than the US average. A cost of living index above 100 means Dayton, Ohio is more expensive.
Sea Island, GA Weather. The average temperature of Sea Island is 67.50Â°F, which is much higher than the Georgia average temperature of 62.30Â°F and is much higher than the national average temperature of 54.45Â°F. Historical Weather.
Today's Mackinac Island sea temperature is 62 Â°F. Statistics for 01 Sep (1981â2005) â mean: 62 Â°F, range: 57 Â°F to 67 Â°F. The water temperature (61 Â°F) at Mackinac Island is quite cool. If the sun does come out as forecast, it should feel warm enough to surf in a good sealed spring wetsuit. Some surfers would prefer to wear gloves and boots too.