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.
Any later than this and the sea temperatures will probably be too cold to go for a swim. In October, the average sea water temperature for the beaches around the island is 23Â°C â thatâs 2Â°C cooler than in September.Despite the decrease in temperature, 23Â°C is more than warm enough to enjoy all sorts of aquatic activities, including swimming, snorkelling and scuba diving.ny later than this and the sea temperatures will probably be too cold to go for a swim. In October, the average sea water temperature for the beaches around the island is 23Â°C â thatâs 2Â°C cooler than in September.