Climate and monthly weather forecastSaint Simons Island, GA

Climate and monthly weather forecast
The climate of Saint Simons Island
Saint Simons Island, Georgia, USA falls under the Köppen climate classification of Cfa, also known as Humid subtropical, with no dry season. This coastal island is exposed to varied weather conditions associated with the subtropical climate. That includes mild winters and hot, humid summers. As a general pattern, this climate undergoes noticeable variations in temperature, precipitation, and relative humidity throughout the year.Analysing the provided climate data, monthly high temperatures range from 60.4°F (15.8°C) in January to 88.7°F (31.5°C) in July. Conversely, the monthly low temperatures fluctuate from 47.7°F (8.7°C) in January to 77.4°F (25.2°C) in August. On average, the annual relative humidity oscillates from 72% in March to 78% in August and December. Rainfall peaks vary considerably throughout the year, with readings fluctuating from a low of 0.59" (15mm) in January to a high of 3.43" (87mm) in August. Snowfall is correspondingly negligible, with barely an occasional day in January or December being marked by this event.
The highlight of Saint Simons Island's climate is the striking occurrence of increased rainfall during the summer months. From June to August, the monthly rainfall crosses the 2" (51mm) mark, reaching the climatic peak of 3.43" (87mm) in August. In contrast, the month of January receives only a minor amount of rainfall, representing the driest period on the island.
The best time to visit Saint Simons Island
The best time to visit Saint Simons Island is undoubtedly from March to May. Around this time, the climate achieves a harmonious balance, with temperature highs ranging between 68.5°F (20.3°C) and 81.1°F (27.3°C) and relative humidity varying from 72% to 75%. The rainfall distribution during these months is well below 1.5" (38mm) per month. The daylight hours progressively increase from 12 in March to 13.7 in May, promising an ample window for sight-seeing. Moreover, the daily sunshine duration extends from 8 hours in March to 10.6 hours in May, enhancing the overall travel experience.The worst time to visit Saint Simons Island
The summer season, particularly between June and August, represents the least favorable time to visit Saint Simons Island. During this time, the average temperature highs soar beyond 86.5°F (30.3°C), while the humidity spikes to 76% to 78%. The precipitation levels are substantially high, crossing the 2.99" (76mm) mark, with August witnessing the peak rainfall of 3.43" (87mm). The cloud cover also reaches a level around 27% during these months, which can diminish the overall scenery.Spring weather in Saint Simons Island
Spring ushers in a moderate climate on Saint Simons Island with pleasing temperatures that fluctuate between highs of 68.5°F (20.3°C) to 81.1°F (27.3°C) and lows of 55.8°F (13.2°C) to 69.1°F (20.6°C), with relatively tender humidity levels sticking between 72% and 75%. The monthly precipitation is moderate, recording values from 0.75" (19mm) to 1.42" (36mm). The daily sunshine duration stretches from 8 hours in March to 10.6 hours by May, supplying inviting conditions for outdoor exploration activities.Summer weather in Saint Simons Island
Summers in Saint Simons Island are characteristically hot and humid, with average high temperatures arising from 81.1°F (27.3°C) in May to 88.7°F (31.5°C) in July. The relative humidity shows a marked increase, figures ranging from 75% to 78%. The rainfall distribution witnesses a significant rise, surpassing 1.42" (36mm) from May and subsequently reaching highs of 3.43" (87mm) in August. Despite the increased precipitation, the daylight and sunshine duration remains high, approximately 14.2 hours and 11 hours respectively, presenting extended periods for leisure and outdoor activities.Autumn weather in Saint Simons Island
Autumn on Saint Simons Island experiences a gradual decrease in temperature and humidity levels. The highest temperature begins at 84.9°F (29.4°C) in September, dropping to 68.9°F (20.5°C) by November. Alongside this, the relative humidity also gradually descends, from 77% in September to 74% by November. The rainfall starts high at 2.8" (71mm) in September and falls to 1.02" (26mm) by November. The daylight hours and sunshine duration also lessen over these months, from 12.3 hours and 8.6 hours respectively in September, to 10.6 hours and 6.1 hours by November.Winter weather in Saint Simons Island
Winter in Saint Simons Island comes with chilled temperatures, shifting between 60.4°F (15.8°C) in December to 64.4°F (18°C) by February, and lows of 47.7°F (8.7°C) in December to 51.1°F (10.6°C) in February. In differentiation with the summer season, the humidity level stands relatively stable between 74% and 78%. The rainfall in winter fluctuates in the range of 0.59" (15mm) to 1.02" (26mm) per month. Strikingly, daylight hours decrease to 10.2 hours by December while the daily sunshine duration drops to 5.8 hours by December, potentially restricting outdoor activities.Weather in January
On Saint Simons Island, the year begins with mild and damp conditions. Differences with February are minimal in temperature aspects, however, more sunlight can be enjoyed in January. A total flotation of 5.9 sunshine hours per day underscores the typically moderate maritime climate of the Georgia coast. Weather in January »Weather in February
February extends the comfortable winter weather of January on Saint Simons Island, though daylight hours elevate slightly and relative damp rises, indicating the inevitable approach of spring. Weather conditions remain generally steady between these two months; nevertheless, gusts of wind are slightly stronger in February. Weather in February »Weather in March
March on Saint Simons Island sees the spring season commence in earnest. A slight elevation in temperature becomes noticeable compared to February, signs of the blooming flora and longer daylight hours start to arrive. March does produce a considerable growth in rainfall when compared to its predecessor. Weather in March »Weather in April
April exhibits a significant jump in temperatures on the Island compared to its March counterpart. This period introduces more sunshine hours while rainfall continues its ascend, culminating in a warm and humid spring month. Hikers and cyclists can take advantage of the increased visibility, remaining steady at 6 miles. Weather in April »Weather in May
May heralds the arrival of summer on Saint Simons Island with noticeable increases in temperature, producing more hot and humid conditions. Compared to April, May offers less rainfall despite warmer temperatures. The daylight extends more, making way for longer excursions, and water lovers enjoy comfortably warm sea temperatures. Weather in May »Weather in June
June carries the heat of May into the beach season of Saint Simons Island along with the rare, yet highest average snowfall at 0.1 day. With the increase in humidity and rains, a tropical ambiance begins to set in. Despite this, June distinguishes itself as the month witnessing the longest daylight duration with 14.2 hours. Weather in June »Weather in July
July carries the tropical conditions of June further, maintaining high humidity and rainfall levels. With the change from June to July, daylight decreases slightly though sea temperatures continue to rise. The high temperature, along with persistent rains, keeps the cloud coverage relatively stable and visibility remains clear across the Island. Weather in July »Weather in August
August prolongs the summer season on Saint Simons Island, with July and August sharing the same intensity of heat. The fluctuation in humidity is quite unmistakable as one transitions from July to August, pairing with a high probability of rainy days. Weather in August »Weather in September
September brings a slow transition from the hot summer temperatures to a more comfortable fall climate on Saint Simons Island. It places a halt on the sequence of increasing rainfall from the summer, causing a reverse. The visible shortening of days and more moderate heat levels differ drastically from the conditions experienced in August. Weather in September »Weather in October
October on Saint Simons Island witnesses a steady decline in temperatures, introducing the livable conditions of fall. The difference in climate becomes evident when compared to September, alongside diminishing rainfall and shorter sunlight hours. Weather in October »Weather in November
November carries forward the temperate fall vibes of October on Saint Simons Island. It starts to showcase a noticeable decline in temperature, and the gloomy climate hints at the onset of winter. A considerable decrease in rainfall days from October to November makes outdoor activities more enjoyable. Weather in November »Weather in December
December sees the onset of winter on Saint Simons Island. The weather grows colder, contrasted with the mild November climate. Rainfall remains moderate, and the daylight hours continue to shorten. The most noticeable feature of December on Saint Simons Island is the sea temperature that drops to 63 degrees F, substantially cooler than November. Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Saint Simons Island, GA
The warmest month (with the highest average high temperature) is July (88.7°F).
The month with the lowest average high temperature is January (60.4°F).
The month with the highest average low temperature is August (77.4°F).
The coldest month (with the lowest average low temperature) is January (47.7°F).
Average pressure
Saint Simons Island, GA
- Average pressure in January:
30.14"Hg - Average pressure in February:
30.11"Hg - Average pressure in March:
30.09"Hg - Average pressure in April:
30.03"Hg - Average pressure in May:
30.02"Hg - Average pressure in June:
29.98"Hg
- Average pressure in July:
30.01"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
29.98"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.11"Hg - Average pressure in December:
30.12"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.98"Hg).
Average wind speed
Saint Simons Island, GA
- Average wind speed in January:
8.8mph - Average wind speed in February:
8.6mph - Average wind speed in March:
8.7mph - Average wind speed in April:
8.8mph - Average wind speed in May:
8.2mph - Average wind speed in June:
7.3mph
- Average wind speed in July:
7.1mph - Average wind speed in August:
6.9mph - Average wind speed in September:
7.6mph - Average wind speed in October:
8.6mph - Average wind speed in November:
8.7mph - Average wind speed in December:
8.6mph
The windiest months (with the highest average wind speed) are January and April (8.8mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).
Average humidity
Saint Simons Island, GA
The months with the highest relative humidity are August and December (78%).
The month with the lowest relative humidity is March (72%).
Average rainfall
Saint Simons Island, GA
- Average rainfall in January:
0.59" - Average rainfall in February:
0.75" - Average rainfall in March:
0.75" - Average rainfall in April:
1.18" - Average rainfall in May:
1.42" - Average rainfall in June:
2.99"
- Average rainfall in July:
2.87" - Average rainfall in August:
3.43" - Average rainfall in September:
2.8" - Average rainfall in October:
1.61" - Average rainfall in November:
1.02" - Average rainfall in December:
1.02"
The wettest month (with the highest rainfall) is August (3.43").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days
Saint Simons Island, GA
- Average rainfall days in January:
8.2 days - Average rainfall days in February:
8.8 days - Average rainfall days in March:
9.2 days - Average rainfall days in April:
10.8 days - Average rainfall days in May:
12.6 days - Average rainfall days in June:
20 days
- Average rainfall days in July:
21.6 days - Average rainfall days in August:
23.3 days - Average rainfall days in September:
19.2 days - Average rainfall days in October:
11.5 days - Average rainfall days in November:
8.6 days - Average rainfall days in December:
9.5 days
The month with the highest number of rainy days is August (23.3 days).
The month with the least rainy days is January (8.2 days).
Average snowfall days
Saint Simons Island, GA
- Average snowfall days in January:
0 days - Average snowfall days in February:
0.1 days - Average snowfall days in March:
0 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0 days - Average snowfall days in December:
0.1 days
The months with the highest number of snowfall days are February and December (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October and November (0 days).
Average sea temperature
Saint Simons Island, GA
The best month for swimming (with the highest average sea temperature) is August (83.4°F).
The coldest month (with the lowest average sea temperature) is February (58.5°F).
Average daylight / Average sunshine
Saint Simons Island, GA
- Average daylight in January:
10h and 24min - Average daylight in February:
11h and 6min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 0min - Average daylight in May:
13h and 42min - Average daylight in June:
14h and 6min
- Average daylight in July:
13h and 54min - Average daylight in August:
13h and 12min - Average daylight in September:
12h and 18min - Average daylight in October:
11h and 24min - Average daylight in November:
10h and 36min - Average daylight in December:
10h and 12min
The month with the longest days is June (Average daylight: 14h and 6min).
The month with the shortest days is December (Average daylight: 10h and 12min).
- Average sunshine in January:
5h and 54min - Average sunshine in February:
7h and 24min - Average sunshine in March:
8h and 0min - Average sunshine in April:
9h and 36min - Average sunshine in May:
10h and 36min - Average sunshine in June:
10h and 54min
- Average sunshine in July:
11h and 0min - Average sunshine in August:
10h and 36min - Average sunshine in September:
8h and 36min - Average sunshine in October:
7h and 6min - Average sunshine in November:
6h and 6min - Average sunshine in December:
5h and 48min
The month with the most sunshine is July (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days
Saint Simons Island, GA
- Average sunshine days in January:
19.8 days - Average sunshine days in February:
17.8 days - Average sunshine days in March:
20.1 days - Average sunshine days in April:
18.1 days - Average sunshine days in May:
16 days - Average sunshine days in June:
7.8 days
- Average sunshine days in July:
6.3 days - Average sunshine days in August:
4.2 days - Average sunshine days in September:
7.4 days - Average sunshine days in October:
17 days - Average sunshine days in November:
17.8 days - Average sunshine days in December:
19.5 days
The month with the most sunshine days is March (20.1 days).
The month with the least sunshine days is August (4.2 days).
Average UV index
Saint Simons Island, GA
The months with the highest UV index are May, June, July, August and September (UV index 7).
The month with the lowest UV index is January (UV index 3).
Average cloud cover
Saint Simons Island, GA
The months with the most cloud cover are February and December (Cloud cover 38).
The months with the least cloud cover are April, May, June and July (Cloud cover 27).
Average visibility
Saint Simons Island, GA
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





