September weather forecastSouth Sumter, SC
September
Weather in September
The first month of the autumn, September, is still a warm month in South Sumter, South Carolina, with temperature in the range of an average low of 66.6°F (19.2°C) and an average high of 83.7°F (28.7°C).Temperature
Transitioning into September, South Sumter experiences an average high-temperature of a moderately hot 83.7°F (28.7°C), marking a minor shift from the preceding month. An average temperature of 66.6°F (19.2°C) is recorded during the nights in September.Heat index
The average heat index in September is estimated at a hot 91.4°F (33°C). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.Heat index guidelines indicate values are for light wind scenarios and shaded regions. 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', gives an indication of how one might feel in terms of heat after considering humidity. This effect is subjective, differing among individuals based on their physical activity and perception of heat, which can be influenced by factors like wind, clothing, and metabolic variances. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.
Humidity
The average relative humidity in September is 75%.Rainfall
In South Sumter, in September, during 14.1 rainfall days, 2.48" (63mm) of precipitation is typically accumulated. Throughout the year, in South Sumter, there are 161.8 rainfall days, and 33.35" (847mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:55 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 7:06 pm EDT.
Sunshine
The average sunshine in September is 8.7h.UV index
In September, the average daily maximum UV index is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The UV index of 6 during September leads to these advisories:
Avoid overexposure. Fair-skinned individuals can burn in under 20 minutes. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
South Sumter, SC
- Average high temperature in September: 83.7°F
The warmest month (with the highest average high temperature) is July (90.7°F).
The month with the lowest average high temperature is January (52.9°F).
- Average low temperature in September: 66.6°F
The month with the highest average low temperature is July (72.9°F).
The coldest month (with the lowest average low temperature) is January (38.1°F).
Average pressure in September
South Sumter, SC
- Average pressure in September: 30.01"Hg
The months with the highest atmospheric pressure are January, November and December (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.97"Hg).
Average wind speed in September
South Sumter, SC
- Average wind speed in September: 6.3mph
The windiest months (with the highest average wind speed) are February and April (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).
Average humidity in September
South Sumter, SC
- Average humidity in September: 75%
The month with the highest relative humidity is May (76%).
The months with the lowest relative humidity are January and November (70%).
Average rainfall in September
South Sumter, SC
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is December (3.58").
The driest month (with the least rainfall) is January (1.89").
Average rainfall days in September
South Sumter, SC
- Average rainfall days in September: 14.1 days
The month with the highest number of rainy days is July (20.1 days).
The month with the least rainy days is October (8.5 days).
Average snowfall in September
South Sumter, SC
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.55").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
South Sumter, SC
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.6 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
South Sumter, SC
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in September
South Sumter, SC
- Average sunshine days in September: 13.5 days
The month with the most sunshine days is October (20.8 days).
The month with the least sunshine days is July (8.8 days).
Average UV index in September
South Sumter, SC
- Average UV index in September: 6
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February and December (UV index 3).
Average cloud cover in September
South Sumter, SC
- Average cloud cover in September: 33
The months with the most cloud cover are February and December (Cloud cover 42).
The month with the least cloud cover is October (Cloud cover 29).
Average visibility in September
South Sumter, SC
- Average visibility in September: 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).





