September weather forecast
Round O, SC

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Weather in September

The first month of the autumn, September, is still a warm month in Round O, South Carolina, with an average temperature fluctuating between 68.5°F (20.3°C) and 85.6°F (29.8°C).

Temperature

Round O, South Carolina, starts September with an average high-temperature of a warm 85.6°F (29.8°C), hinting at a minimal fluctuation from August. The nighttime temperature in Round O, South Carolina, during September, averages of 68.5°F (20.3°C).

Heat index

The heat index for September is evaluated at a fiery hot 96.8°F (36°C). Implement additional cautionary measures, heat cramps and heat exhaustion could occur. Prolonged activity might induce heatstroke.
From a standpoint of the heat index, values pertain to shaded conditions and mild breezes. Direct sunlight exposure may cause a 15 Fahrenheit (8 Celsius) degrees rise in the heat index.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', embodies the combination of air temperature and moisture content to illustrate perceived heat. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. 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 are quite important for babies and toddlers. Children usually face more risks than adults as their ability to sweat is less. Additionally, their larger skin surface in relation to their petite bodies and higher heat output due to their activities increases their vulnerability.
To offset high temperatures, the human body releases sweat which, upon evaporation, cools it down. With higher relative humidity, the rate of evaporation is reduced, resulting in increased heat retention in the body compared to drier air. Overheating and potential dehydration arise when body heat gain eclipses its release capability.

Humidity

In September, the average relative humidity in Round O, South Carolina, is 76%.

Rainfall

In Round O, South Carolina, in September, during 14.2 rainfall days, 1.89" (48mm) of precipitation is typically accumulated. In Round O, during the entire year, the rain falls for 149.7 days and collects up to 21.5" (546mm) of precipitation.

Snowfall

March through December are months without snowfall in Round O, South Carolina.

Daylight

The average length of the day in September in Round O is 12h and 22min.
On the first day of September in Round O, sunrise is at 6:57 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 7:07 pm EDT.

Sunshine

The average sunshine in September in Round O is 8.7h.

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 the average person.
Note: An average UV index of 6 in September transforms into this advice:
Prevent overexposure. Protection from the sun's harmful effects is needed. Stay in the shade and limit direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is particularly strong. Remember, however, that shade structures may not provide complete protection. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Resources | Updated: Feb 13, 2024 | Published by: Weather U.S.

Frequently asked questions

How hot does it get in Round O in September?

In September, the average high-temperature and low-temperature in Round O, South Carolina, are 85.6°F (29.8°C) and 68.5°F (20.3°C) respectively. The average heat index (a.k.a. 'feels like', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, in September is evaluated at 96.8°F (36°C).

What is the average humidity in September in Round O?

The average relative humidity in September is 76%.

How much does it rain in Round O in September?

In Round O, South Carolina, in September, during 14.2 rainfall days, 1.89" (48mm) of precipitation is typically accumulated.

When it does not snow in Round O?

In Round O, snow does not fall in March through December.

What is the average length of the day in September in Round O?

In Round O, the average day length in September is 12h and 22min.

What time are sunrise and sunset in September in Round O?

In September, on the first day of the month, sunrise is at 6:57 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 7:07 pm EDT.

How many hours of sunshine does Round O have in September?

In September, the average sunshine duration is 8.7h.

What is the UV index reading in September in Round O?

The average daily maximum UV index in September in Round O is 6. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Round O, SC

Average temperature in September - Round O, SC
  • Average high temperature in September: 85.6°F

The warmest month (with the highest average high temperature) is July (91.8°F).
The month with the lowest average high temperature is January (56.1°F).

  • Average low temperature in September: 68.5°F

The month with the highest average low temperature is July (73.4°F).
The coldest month (with the lowest average low temperature) is January (39.9°F).

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Average pressure in September
Round O, SC

Average pressure in September - Round O, 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 (29.97"Hg).

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Average wind speed in September
Round O, SC

Average wind speed in September - Round O, SC
  • Average wind speed in September: 5.3mph

The windiest month (with the highest average wind speed) is April (6.7mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

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Average humidity in September
Round O, SC

Average humidity in September - Round O, SC
  • Average humidity in September: 76%

The months with the highest relative humidity are August and December (77%).
The months with the lowest relative humidity are January, March and November (72%).

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Average rainfall in September
Round O, SC

Average rainfall in September - Round O, SC
  • Average rainfall in September: 1.89"

The wettest month (with the highest rainfall) is August (3.15").
The driest month (with the least rainfall) is November (0.75").

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Average rainfall days in September
Round O, SC

Average rainfall days in September - Round O, SC
  • Average rainfall days in September: 14.2 days

The month with the highest number of rainy days is July (21.1 days).
The month with the least rainy days is November (6.2 days).

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Average snowfall in September
Round O, SC

Average snowfall in September - Round O, SC
  • Average snowfall in September: 0"

The months with the highest snowfall are January and February (0.12").
The months with the least snowfall are March, April, May, June, July, August, September, October, November and December (0").

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Average snowfall days in September
Round O, SC

Average snowfall days in September - Round O, SC
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (0.4 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).

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Average daylight in September /
Average sunshine in September
Round O, SC

Average daylight in September / Average sunshine in September - Round O, SC
  • Average daylight in September: 12h and 2min

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: 8h and 4min

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 30min).

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Average sunshine days in September
Round O, SC

Average sunshine days in September - Round O, SC
  • Average sunshine days in September: 13.5 days

The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is July (6.9 days).

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Average UV index in September
Round O, SC

Average UV index in September - Round O, SC
  • Average UV index in September: 6

The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January and December (UV index 3).

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Average cloud cover in September
Round O, SC

Average cloud cover in September - Round O, SC
  • Average cloud cover in September: 31

The month with the most cloud cover is December (Cloud cover 42).
The months with the least cloud cover are July and October (Cloud cover 29).

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Average visibility in September
Round O, SC

Average visibility in September - Round O, SC
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).

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Round O, South Carolina, USA

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