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.
If Januaryâs cold, but mild, temperatures are not enough of a deterrent to go swimming, maybe the sea temperature will be. The average sea temperature this month is 16Â°C (61Â°F), which feels quite cold to most people, even for just a quick dip in the water.