Charleston
South Carolina, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Charleston, SC

Trees along both sides of a street in Charleston, South Carolina, in the twilight light
Trees along both sides of a street in Charleston, South Carolina, in the twilight light
Septiembre, the first month of the autumn, in Charleston, is still a warm month, with average temperature fluctuating between 67.3°F (19.6°C) and 84.7°F (29.3°C).

Temperature

In Septiembre, the average high-temperature is practically the same as in Agosto - a moderately hot 84.7°F (29.3°C). In Septiembre, in Charleston, the average low-temperature is 67.3°F (19.6°C).

Heat index

The average heat index in Septiembre is evaluated at a sweltering 95.4°F (35.2°C). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Note that heat index values are valued for light wind and location in the shade. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'felt air temperature', 'feels like', or 'real feel', is a measure that combines both air temperature and relative humidity into a single value that indicates how hot the weather feels. This effect is individual, with diverse people perceiving weather differently for numerous reasons (differences in body mass, height, and shape, metabolic differences, clothing), and activity. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. With a lot of moisture in the air, the evaporation process is not as effective, and the body does not cool down as efficiently, creating a perception of overheating. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

In Septiembre, the average relative humidity is 78.2%.

Rainfall

In Charleston, during 10 rainfall days, 6.1" (154.9mm) of precipitation is typically accumulated. Throughout the year, in Charleston, South Carolina, there are 112.7 rainfall days, and 51.03" (1296.1mm) of precipitation is accumulated.

Snowfall

In Charleston snow does not fall in Enero, Marzo through Noviembre.

Ocean temperature

In Charleston, the average water temperature is 81.7°F (27.6°C).
Note: For any water activity, surface water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered as excellent and extremely pleasant for lengthened periods.

Daylight

In Septiembre, the average length of the day in Charleston, South Carolina, is 12.4h.

Sunshine

In Septiembre, the average sunshine in Charleston, South Carolina, is 7.3h.

UV index

In Charleston, the average daily maximum UV index is 8. A UV Index value of 8 to 10 symbolizes a very high health risk from the exposure to the Sun's UV rays for average individuals.
Note: The average daily UV index of 8 in Septiembre transform into the following instructions:
Take extra precautions. Fair-skinned individuals may get burned in less than 10 minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Caution! The reflection of sand and water significantly increases the intensity of the Sun's UV radiation.

What is the temperature in Septiembre in Charleston?

In Charleston, in Septiembre, the average high-temperature is 84.7°F (29.3°C), and the average low-temperature is 67.3°F (19.6°C). In Septiembre, the average heat index (a.k.a. 'feels like', 'apparent temperature'), that combines relative humidity and air temperature, is appraised at 95.4°F (35.2°C).

What is the average humidity in Septiembre in Charleston?

In Charleston, South Carolina, the average relative humidity in Septiembre is 78.2%.

How many days does it rain in Septiembre in Charleston?

In Charleston, South Carolina, during Septiembre, the rain falls for 10 days and regularly aggregates up to 6.1" (154.9mm) of precipitation.

When it does not snow in Charleston?

Enero, Marzo through Noviembre are months without snowfall in Charleston, South Carolina.

How warm is the water in Septiembre in Charleston?

In Charleston, in Septiembre, the average water temperature is 81.7°F (27.6°C). For any water activity, surface water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered as excellent and extremely pleasant for lengthened periods.

How many hours of daylight does Charleston have in Septiembre?

In Charleston, the average length of the day in Septiembre is 12.4h.

How many hours of sunshine does Charleston have in Septiembre?

In Septiembre, the average sunshine in Charleston, South Carolina, is 7.3h.

What is the UV index reading in Septiembre in Charleston?

The average daily maximum UV index in Septiembre is 8. A UV Index of 8 to 10 symbolizes a very high health threat from unprotected exposure to the UV radiation.
Average temperature in September - Charleston, SC
  • Average high temperature in September: 84.8°F

The warmest month (with the highest average high temperature) is July (91.1°F).
The month with the lowest average high temperature is January (59°F).

  • Average low temperature in September: 67.2°F

The month with the highest average low temperature is July (73°F).
The coldest month (with the lowest average low temperature) is January (37.5°F).

Average humidity in September - Charleston, SC
  • Average humidity in September: 78.2%

The month with the highest relative humidity is August (78.9%).
The month with the lowest relative humidity is February (67.4%).

Average rainfall in September - Charleston, SC
  • Average rainfall in September: 6.1"

The wettest month (with the highest rainfall) is August (7.2").
The driest month (with the lowest rainfall) is November (2.4").

Average rainfall days in September - Charleston, SC
  • Average rainfall days in September: 10 days

The month with the highest number of rainy days is August (13.2 days).
The month with the lowest number of rainy days is November (7 days).

Average snowfall in September - Charleston, SC
  • Average snowfall in September: 0"

The month with the highest snowfall is December (0.5").
Months with the lowest snowfall are January, March, April, May, June, July, August, September, October and November (0").

Average snowfall days in September - Charleston, SC
  • Average snowfall days in September: 0 days

Months with the highest number of snowfall days are February and December (0.2 days).
Months with the lowest number of snowfall days are March, April, May, June, July, August, September, October and November (0 days).

Average sea temperature in September - Charleston, SC
  • Average sea temperature in September: 81.7°F

The best month for swimming (with the highest average sea temperature) is August (83.5°F).
The coldest month (with the lowest average sea temperature) is February (61.9°F).

Average daylight in September / Average sunshine in September - Charleston, SC
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.3h).
The month with shortest days is December (Average daylight: 10h).

  • Average sunshine in September: 7.3h

The month with most sunshine is May (Average sunshine: 9.5h).
The month with least sunshine is December (Average sunshine: 5.5h).

Average UV index in September - Charleston, SC
  • Average UV index in September: 8

Months with the highest UV index are June, July and August (UV index 10).
Months with the lowest UV index are January and December (UV index 3).