Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
During September, the average high-temperature is a warm 83.7°F (28.7°C), maintaining a close resemblance to that of the preceding month. The average temperature drops to a comfortable 66.6°F (19.2°C) during the night in the month of September.Heat index
September's heat index is estimated at a tropical 91.4°F (33°C). Exercise extra preventive actions, heat cramps and heat exhaustion are plausible. Continuous activity could result in heatstroke.The heat index's values are generally associated with conditions in shade and light breezes. If directly exposed to the sun, the heat index could rise by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is a numerical representation of warmth when taking temperature and moisture levels into account. An individual's perception of weather can be affected by a variety of elements including metabolic differences, being pregnant, and their level of physical exertion. When in direct sunlight, one should be cautious as it can raise the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Children frequently underestimate the importance of resting and drinking fluids. Thirst is a symptom of advanced dehydration - hence the need to hydrate regularly, especially during protracted physical exercises.
Humidity
In Sumter, the average relative humidity in September is 75%.Rainfall
In Sumter, in September, during 14.1 rainfall days, 2.48" (63mm) of precipitation is typically accumulated. In Sumter, during the entire year, the rain falls for 161.8 days and collects up to 33.35" (847mm) of precipitation.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 the month, sunrise is at 6:55 am and sunset at 7:46 pm. On the last day of September, in Sumter, sunrise is at 7:15 am and sunset at 7:06 pm EDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
In September, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for the ordinary person.Note: A maximum daily UV index of 6 during September morphs into the following directions:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. Stay out of direct sunlight between 10 a.m. and 4 p.m., when UV radiation is most intense, and remember that not all shade structures provide complete protection. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is September?
What is the average humidity in September in Sumter?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
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
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
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
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
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
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
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
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
Sumter, SC
- Average daylight in September: 12h and 2min
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 4min
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
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
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
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
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).
Sumter, South Carolina, USA
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