Climate and monthly weather forecast
Saint Simons Island, GA

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A long pier with a large shed on the St. Simons Island, Georgia, the rocks and seawater and colorful sunset clouds in the sky above
A long pier with a large shed on the St. Simons Island, Georgia, the rocks and seawater and colorful sunset clouds in the sky above

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 »
Updated: Jul 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What time of the year is the coldest?

In Saint Simons Island, January registers the lowest temperatures, averaging 60.4°F (15.8°C) at the peak and 47.7°F (8.7°C) at the lowest.

What is the driest month?

The month with the least rainfall is January, when the rain falls for 8.2 days and typically collects 0.59" (15mm) of precipitation.

How many days does it rain?

In Saint Simons Island, during the entire year, the rain falls for 163.3 days and collects up to 20.43" (519mm) of precipitation.

When it does not snow?

January, March through November are months without snowfall.

How many days does it snow?

In Saint Simons Island, during the entire year, snow falls for 0.2 days.

When is the lowest UV index?

With an average maximum UV index of 3, January is the month with the lowest UV index in Saint Simons Island.

When does it snow?

February and December are months with snowfall.

When does it snow the most?

The months with the most snowfall days in Saint Simons Island, Georgia, are February and December, with an average of 0.1 snowfall days.

When is the ocean coldest in Saint Simons Island?

February is the month with the coldest seawater, with an average ocean temperature of 58.6°F (14.8°C).

What is the least humid month?

March is the least humid month in Saint Simons Island, with an average relative humidity of 72%.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.

What are the months with the highest UV index?

May through September, with an average maximum UV index of 7, are months with the highest UV index.

When are the longest days?

With an average of 14h and 6min of daylight, June has the longest days of the year.

What is the hottest time of year in Saint Simons Island?

Saint Simons Island's warmest weather arrives in July, when temperatures average a high of 88.7°F (31.5°C) and a low of 77°F (25°C).

What month has the most sunshine?

With an average of 11h of sunshine, July has the most sunshine of the year.

What is the most humid month?

The months with the highest humidity are August and December, with an average relative humidity of 78%.

What is the wettest month?

August is the month with the most rainfall. Rain falls for 23.3 days and accumulates 3.43" (87mm) of precipitation.

What month is the ocean warmest?

The month with the warmest seawater is August, with an average ocean temperature of 83.5°F (28.6°C).

What is the month with the shortest days?

The month with the shortest days in Saint Simons Island, Georgia, is December, with an average of 10h and 12min of daylight.

What is the month with the least sunshine?

The month with the least sunshine in Saint Simons Island, Georgia, is December, with an average of 5.8h of sunshine.
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Average temperature
Saint Simons Island, GA

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 - Saint Simons Island, GA

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 - Saint Simons Island, GA

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

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 - Saint Simons Island, GA

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 - Saint Simons Island, GA

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 - Saint Simons Island, GA

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

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 / Average sunshine - Saint Simons Island, GA

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).

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 - Saint Simons Island, GA

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

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

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

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).

Saint Simons Island, Georgia, USA

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