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
A mild shift in the average high-temperature occurs in September, reducing from a hot 87.4°F (30.8°C) in August to a moderately hot 81.9°F (27.7°C). Charleston's temperature in September lowers to a consistent average of 61°F (16.1°C) during the nights.Heat index
The average heat index in September is evaluated at a tropical 87.8°F (31°C). One might feel worn out with persistent exposure and activity, resulting in heat cramps.Factoring in the heat index, values are geared towards shaded areas with light breezes. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. The individual's impression of temperature can be shaped by additional aspects such as metabolic variations, physical activity, and clothing. Considering the impact of direct sunlight, it's possible for the heat index to surge by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Kids are generally in more danger than adults because they perspire less. Their large skin surface area compared to their small bodies and the excessive heat due to their actions raises their risk.
Humidity
June through November, with an average relative humidity of 75%, are the least humid months in Charleston, Tennessee.Rainfall
September is the month with the least rainfall in Charleston. Rain falls for 11.1 days and accumulates 1.3" (33mm) of precipitation.Snowfall
In Charleston, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 23min.On the first day of September, sunrise is at 7:12 am and sunset at 8:05 pm. On the last day of the month, sunrise is at 7:33 am and sunset at 7:23 pm EDT.
Sunshine
In Charleston, the average sunshine in September is 8.6h.UV index
In Charleston, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 5 during September translates into the following directions:
Ensure safety - Sun damage prevention is strongly urged. To protect against the Sun's most potent rays, avoid direct exposure around midday. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Charleston?
What is the least humid month in Charleston?
What is the average humidity in September in Charleston?
What is the driest month in Charleston?
How many days does it rain in September in Charleston?
When it does not snow in Charleston?
What is the average length of the day in September in Charleston?
What time are sunrise and sunset in September in Charleston?
How long on average sun shines in September in Charleston?
What is the UV index intensity in September in Charleston?
Average temperature in September
Charleston, TN
- Average high temperature in September: 81.9°F
The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (46.4°F).
- Average low temperature in September: 61°F
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (30.9°F).
Average pressure in September
Charleston, TN
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in September
Charleston, TN
- Average wind speed in September: 4.1mph
The windiest month (with the highest average wind speed) is February (6.6mph).
The calmest month (with the lowest average wind speed) is August (3.8mph).
Average humidity in September
Charleston, TN
- Average humidity in September: 75%
The month with the highest relative humidity is December (80%).
The months with the lowest relative humidity are June, July, August, September, October and November (75%).
Average rainfall in September
Charleston, TN
- Average rainfall in September: 1.3"
The wettest month (with the highest rainfall) is July (2.64").
The driest month (with the least rainfall) is September (1.3").
Average rainfall days in September
Charleston, TN
- Average rainfall days in September: 11.1 days
The month with the highest number of rainy days is July (17 days).
The month with the least rainy days is November (7.3 days).
Average snowfall in September
Charleston, TN
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.75").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Charleston, TN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.7 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Charleston, TN
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).
Average sunshine days in September
Charleston, TN
- Average sunshine days in September: 16.4 days
The months with the most sunshine days are October and November (21.2 days).
The month with the least sunshine days is July (11.6 days).
Average UV index in September
Charleston, TN
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in September
Charleston, TN
- Average cloud cover in September: 31
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is June (Cloud cover 29).
Average visibility in September
Charleston, TN
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, May and December (5mi).
Charleston, Tennessee, USA
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