September weather forecastCharleston Heights, SC
September
Weather in September
The first month of the autumn, September, is still a warm month in Charleston Heights, South Carolina, with temperature in the range of an average high of 84.4°F (29.1°C) and an average low of 72°F (22.2°C).Temperature
The shift to September signals an average high-temperature of a warm 84.4°F (29.1°C), subtly varied from August's 88.3°F (31.3°C). Charleston Heights, during the nights of September, experiences an average temperature drop to an agreeable 72°F (22.2°C).Heat index
The heat index value for September is evaluated at a tropical 93.2°F (34°C). Implement heightened safety measures - risk of heat exhaustion and heat cramps is increased. Prolonged activity may result in heatstroke.Note that heat index values are valued for light wind and location in the shade. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is achieved by amalgamating air temperature with the relative humidity readings. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. Exposure to direct sun rays can influence the heat you feel, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Young ones are generally more prone to risk than adults due to their reduced ability to sweat. Their large skin surface area relative to their diminutive bodies and elevated heat production from their activities further enhance this risk.
Humidity
The average relative humidity in September is 75%.Rainfall
In Charleston Heights, during September, the rain falls for 14.8 days and regularly aggregates up to 2.76" (70mm) of precipitation. Throughout the year, there are 154.4 rainfall days, and 23.43" (595mm) of precipitation is accumulated.Snowfall
In Charleston Heights, South Carolina, snow does not fall in March through November.Daylight
The average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:54 am and sunset at 7:44 pm. On the last day of September, sunrise is at 7:13 am and sunset at 7:05 pm EDT.
Sunshine
In Charleston Heights, the average sunshine in September is 9h.UV index
In September, the average daily maximum UV index is 6. A UV Index value of 6 to 7 symbolizes a high threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: The average daily UV index of 6 in September transforms into the following instructions:
Eschew overexposure. Those with light skin may suffer burns in fewer than 20 minutes. Try to minimize direct Sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Also note that objects like parasols or canopies might not provide complete sun protection. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Charleston Heights, SC
- Average high temperature in September: 84.4°F
The warmest month (with the highest average high temperature) is July (89.6°F).
The month with the lowest average high temperature is January (56.8°F).
- Average low temperature in September: 72°F
The month with the highest average low temperature is July (76.5°F).
The coldest month (with the lowest average low temperature) is January (42.8°F).
Average pressure in September
Charleston Heights, SC
- Average pressure in September: 30"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 September
Charleston Heights, SC
- Average wind speed in September: 7.1mph
The windiest month (with the highest average wind speed) is April (8.3mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Charleston Heights, SC
- Average humidity in September: 75%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is March (72%).
Average rainfall in September
Charleston Heights, SC
- Average rainfall in September: 2.76"
The wettest month (with the highest rainfall) is August (4.29").
The driest month (with the least rainfall) is January (0.67").
Average rainfall days in September
Charleston Heights, SC
- Average rainfall days in September: 14.8 days
The month with the highest number of rainy days is August (22.7 days).
The month with the least rainy days is November (6.9 days).
Average snowfall days in September
Charleston Heights, SC
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Charleston Heights, SC
- Average daylight in September: 12h and 24min
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 September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).
Average sunshine days in September
Charleston Heights, SC
- Average sunshine days in September: 11 days
The month with the most sunshine days is November (20.4 days).
The month with the least sunshine days is August (6.1 days).
Average UV index in September
Charleston Heights, SC
- Average UV index in September: 6
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 September
Charleston Heights, SC
- Average cloud cover in September: 30
The month with the most cloud cover is December (Cloud cover 40).
The months with the least cloud cover are June and July (Cloud cover 26).
Average visibility in September
Charleston Heights, 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).





