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
The onset of September notes an average high-temperature of a warm 81.7°F (27.6°C), subtly shifted from August's 86.4°F (30.2°C). An average low-temperature of 62.2°F (16.8°C) is observed during September nights.Heat index
The average heat index in September is calculated to be a hot 86°F (30°C). Exposure and extended activity could potentially cause a state of fatigue and lead to heat cramps.Metrics for the heat index primarily focus on shaded spots and light wind conditions. Direct sunlight exposure may cause a 15 Fahrenheit (8 Celsius) degrees rise in the heat index.
Note: The heat index, also known as 'apparent temperature' or 'feels like', offers an insight into how hot it feels when we factor in moisture content. The perception of temperature can be subjective, varying based on activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Children typically face more danger than adults as their sweat production is usually lower. Additionally, the bigger skin surface compared to their small size and the increased heat due to their activeness exacerbate the risk.
Humidity
In Charleston, the average relative humidity in September is 72%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.4 days and typically collects 1.22" (31mm) of precipitation.Snowfall
In Charleston, snow does not fall in May through October.Daylight
In September, the average length of the day is 12h and 24min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:25 pm. On the last day of September, sunrise is at 6:52 am and sunset at 6:41 pm CDT.
Sunshine
In Charleston, the average sunshine in September is 9.7h.UV index
The average daily maximum UV index in September in Charleston is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: A maximum high UV index of 5 in September translates into the following recommendations:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September?
How many hours of sunshine does Charleston have in September?
What is the UV index reading in September?
Average temperature in September
Charleston, MO
- Average high temperature in September: 81.7°F
The warmest month (with the highest average high temperature) is July (88.2°F).
The month with the lowest average high temperature is January (41.5°F).
- Average low temperature in September: 62.2°F
The month with the highest average low temperature is July (70.2°F).
The coldest month (with the lowest average low temperature) is January (28.8°F).
Average pressure in September
Charleston, MO
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Charleston, MO
- Average wind speed in September: 6.4mph
The windiest months (with the highest average wind speed) are January, February and March (9.3mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).
Average humidity in September
Charleston, MO
- Average humidity in September: 72%
The months with the highest relative humidity are March and May (78%).
The month with the lowest relative humidity is October (69%).
Average rainfall in September
Charleston, MO
- Average rainfall in September: 1.22"
The wettest month (with the highest rainfall) is April (3.9").
The driest month (with the least rainfall) is September (1.22").
Average rainfall days in September
Charleston, MO
- Average rainfall days in September: 11.4 days
The month with the highest number of rainy days is May (16.4 days).
The month with the least rainy days is January (9.4 days).
Average snowfall in September
Charleston, MO
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.69").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Charleston, MO
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Charleston, MO
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 9h and 4min
The months with the most sunshine are June and July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Charleston, MO
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is October (19.5 days).
The month with the least sunshine days is May (12.1 days).
Average UV index in September
Charleston, MO
- 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 and December (UV index 2).
Average cloud cover in September
Charleston, MO
- Average cloud cover in September: 26
The months with the most cloud cover are February and March (Cloud cover 48).
The month with the least cloud cover is June (Cloud cover 25).
Average visibility in September
Charleston, MO
- 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).
Charleston, Missouri, USA
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