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St. Simons Island weather in December

Weather in St. Simons Island: December

Average day temperature: 62.5°F
Average night temperature: 53.3°F
Sea water temperature: 59.3°F
Number of sunny days: 13 days
Day length: 10.1 - 10.3 hours
Number of rainy days: 2 days
Precipitation totals: 0.7 in.

Air temperature in December, °F

Show year:
2025
2024
2023

The highest day temperature during December of 2025 was 74°F. At the same time the lowest night temperature was 32°F. Daily and nightly averages during December were 61.7°F and 50.2°F.

Sea water temperature in St. Simons Island in December, °F

Show year:
2025
2024
2023

The average sea water temperature in December of 2025 was 57.9°F. The highest and lowest sea temperatures during the month were 64.0°F and 53.1°F.

Sunny, partly cloudy and cloudy days

Mostly all days in December are sunny but cloudy days are also possible.

Precipitation total in December, in.

Precipitation total value in St. Simons Island in December is 0.7 in. Other months of the year show relatively similar values.

Wind speed in December, mph

The average wind speed value in December is 6.8 mph It makes December most windy month of the year.

Average sunny hours

This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in December is: 6.0.

Best time for vacation in St. Simons Island

Sunniest months:
October 15 days
January 14 days
March 14 days
Warmest months:
July 88.3 °F
August 86.9 °F
June 86.1 °F
Warmest sea temp:
August 85.1 °F
July 84.6 °F
September 82.0 °F
Coldest months:
January 59.8 °F
December 62.5 °F
February 64.8 °F
Rainiest months:
August 5 days
July 5 days
September 4 days
Windiest months:
December 6.8 mph
October 6.7 mph
January 6.7 mph

St. Simons Island on a weather map

St. Simons Island
+66°F
E 4 mph
Feels like: +66°F
Precip.: 0%
Places in USA:
Name
°F
+36°F
+75°F
+75°F
+59°F
+59°F
+70°F
+75°F
+70°F
+28°F
+57°F
+52°F
+66°F
+66°F
+70°F
+41°F
24 Hours Forecast
St. Simons Island
Local time: 21:15
December 28, sunday
0000
64°F
E
4 mph
0300
64°F
SE
3 mph
0600
64°F
SE
2 mph
0900
64°F
SW
2 mph
1200
66°F
N
3 mph
1500
68°F
N
4 mph
1800
64°F
N
5 mph
2100
61°F
N
6 mph
Units of measurement: °C / °F