August weather forecastSullivan's Island, SC
August
Weather in August
The last month of the summer, August, is also a moderately hot month in Sullivan's Island, South Carolina, with an average temperature ranging between min 78.1°F (25.6°C) and max 85.8°F (29.9°C).Temperature
The average high-temperature is a moderately hot 85.8°F (29.9°C) in August, hardly different from the 86.5°F (30.3°C) recorded in July. A modest nighttime temperature average of 78.1°F (25.6°C) characterizes August.Heat index
The heat index value for August is appraised at a torrid 98.6°F (37°C). Implement additional preventive actions, heat cramps and heat exhaustion are potential hazards. Heatstroke could follow prolonged activity.Observations indicate that the heat index values are for shady locations with light wind. Heat index values might soar by up to 15 Fahrenheit (8 Celsius) degrees with exposure to direct sunshine.
Note: The heat index, also known as 'apparent temperature' or 'real feel', represents the fusion of temperature and moisture in the air to suggest how warm it feels. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. Sunshine, when direct, has the potential to intensify weather effects, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
In high temperatures, perspiration kicks in, allowing the human body to cool down through the evaporation of sweat. When relative humidity is on the rise, it curtails evaporation, thereby reducing the heat elimination from the body and causing the feeling of being excessively hot. Accumulating more heat than the body can dissipate leads to an uptick in body temperature, with potential heat stress consequences.
Humidity
In Sullivan's Island, the average relative humidity in August is 77%.Rainfall
The month with the most rainfall is August, when the rain falls for 25.9 days and typically aggregates up to 8.23" (209mm) of precipitation.Snowfall
In Sullivan's Island, snow does not fall in March through December.Daylight
In Sullivan's Island, the average length of the day in August is 13h and 19min.On the first day of August, sunrise is at 6:33 am and sunset at 8:17 pm. On the last day of the month, sunrise is at 6:53 am and sunset at 7:45 pm EDT.
Sunshine
In August, the average sunshine is 10.8h.UV index
May through August, with an average maximum UV index of 7, are months with the highest UV index. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for average individuals.Note: The UV index of 7 during August leads to these advisories:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. To the best of your ability, limit your exposure to the sun between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Sullivan's Island, SC
- Average high temperature in August: 85.8°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (57°F).
- Average low temperature in August: 78.1°F
The month with the highest average low temperature is July (78.3°F).
The coldest month (with the lowest average low temperature) is January (45.5°F).
Average pressure in August
Sullivan's Island, SC
- Average pressure in August: 29.99"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in August
Sullivan's Island, SC
- Average wind speed in August: 8.4mph
The windiest months (with the highest average wind speed) are March and April (10.3mph).
The calmest month (with the lowest average wind speed) is August (8.4mph).
Average humidity in August
Sullivan's Island, SC
- Average humidity in August: 77%
The month with the highest relative humidity is December (78%).
The months with the lowest relative humidity are January and March (73%).
Average rainfall in August
Sullivan's Island, SC
- Average rainfall in August: 8.23"
The wettest month (with the highest rainfall) is August (8.23").
The driest month (with the least rainfall) is January (1.42").
Average rainfall days in August
Sullivan's Island, SC
- Average rainfall days in August: 25.9 days
The month with the highest number of rainy days is August (25.9 days).
The month with the least rainy days is November (8.5 days).
Average snowfall days in August
Sullivan's Island, SC
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in August /
Average sunshine in August
Sullivan's Island, SC
- Average daylight in August: 13h and 18min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in August: 10h 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 42min).
Average sunshine days in August
Sullivan's Island, SC
- Average sunshine days in August: 2.8 days
The month with the most sunshine days is January (19.3 days).
The month with the least sunshine days is August (2.8 days).
Average UV index in August
Sullivan's Island, SC
- Average UV index in August: 7
The months with the highest UV index are May, June, July and August (UV index 7).
The month with the lowest UV index is January (UV index 3).
Average cloud cover in August
Sullivan's Island, SC
- Average cloud cover in August: 29
The month with the most cloud cover is December (Cloud cover 39).
The month with the least cloud cover is June (Cloud cover 25).
Average visibility in August
Sullivan's Island, SC
- Average visibility in August: 6mi
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).





