September weather forecastMount Pleasant, SC
September
Weather in September
It's the beginning of fall in September in Mount Pleasant, broadly characterized by the decrease in daily high temperature down to 83.3°F (28.5°C). The ambiance feels different as the ravages of summer simmer down to bring about shorter days and relieving winds. The transition to autumn primes the city’s weather to welcome cooler temperatures and diminishing rainfall. As one moves towards October, the decrease in temperature and receding sunlight hours become more distinctive. A hike in absolute atmospheric pressure can also be noticed towards the end of the month indicating a deep dive into fall.Temperature
The transition from August to September in Mount Pleasant sees average high-temperatures adjusting to a moderately hot 83.3°F (28.5°C), from a not significantly different 86.7°F (30.4°C). September's nights observe an average temperature of 73.6°F (23.1°C).Heat index
September's average heat index is calculated to be a hot 91.4°F (33°C). Adopt heightened safety measures, heat cramps and heat exhaustion may occur. Sustained activity might cause heatstroke.Understand that the heat index values take into account shaded locations and mild winds. With direct sunlight, the heat index could increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is derived by integrating air temperature with the existing relative humidity to express the perceived warmth. A person's impression of weather can be affected by numerous aspects, among them metabolic variations, pregnancy, and activity levels. It is essential to be conscious of the fact that direct sunlight can intensify the felt heat, leading to an elevation in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Younglings frequently fail to recognize the requirement to rest and rehydrate. Thirst emerges late in dehydration - it is imperative to keep hydration levels high, particularly during extended physical exertions.
Humidity
The average relative humidity in September in Mount Pleasant is 76%.Rainfall
In September, the rain falls for 19.4 days. Throughout September, 5.47" (139mm) of precipitation is accumulated. Throughout the year, there are 182.9 rainfall days, and 44.69" (1135mm) of precipitation is accumulated.Snowfall
In Mount Pleasant, snow does not fall in March through November.Daylight
The average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:54 am and sunset at 7:43 pm. On the last day of September, in Mount Pleasant, sunrise is at 7:13 am and sunset at 7:04 pm EDT.
Sunshine
The average sunshine in September in Mount Pleasant is 9.2h.UV index
In Mount Pleasant, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum UV index, 6 during September, leads to the following recommendations:
Adopt measures and apply sun safety strategies. Shielding from skin and eye damage is necessary. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is particularly strong, noting that parasols or canopies may not offer total sun protection. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mount Pleasant, SC
- Average high temperature in September: 83.3°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is January (57.2°F).
- Average low temperature in September: 73.6°F
The month with the highest average low temperature is July (77.9°F).
The coldest month (with the lowest average low temperature) is January (45.1°F).
Average pressure in September
Mount Pleasant, 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 (29.98"Hg).
Average wind speed in September
Mount Pleasant, SC
- Average wind speed in September: 8.6mph
The windiest month (with the highest average wind speed) is April (9.8mph).
The calmest month (with the lowest average wind speed) is August (7.8mph).
Average humidity in September
Mount Pleasant, SC
- Average humidity in September: 76%
The month with the highest relative humidity is December (78%).
The months with the lowest relative humidity are January and March (73%).
Average rainfall in September
Mount Pleasant, SC
- Average rainfall in September: 5.47"
The wettest month (with the highest rainfall) is August (8.03").
The driest month (with the least rainfall) is January (1.38").
Average rainfall days in September
Mount Pleasant, SC
- Average rainfall days in September: 19.4 days
The month with the highest number of rainy days is August (25.8 days).
The month with the least rainy days is November (8.6 days).
Average snowfall in September
Mount Pleasant, SC
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.3").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Mount Pleasant, SC
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Mount Pleasant, SC
- Average daylight in September: 12h and 24min
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: 9h and 12min
The months with the most sunshine are June and July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in September
Mount Pleasant, SC
- Average sunshine days in September: 8.1 days
The months with the most sunshine days are January and November (19.3 days).
The month with the least sunshine days is August (3 days).
Average UV index in September
Mount Pleasant, SC
- Average UV index in September: 6
The months with the highest UV index are May, June, July and August (UV index 7).
The month with the lowest UV index is January (UV index 3).
Average cloud cover in September
Mount Pleasant, SC
- Average cloud cover in September: 29
The month with the most cloud cover is December (Cloud cover 39).
The months with the least cloud cover are June and July (Cloud cover 26).
Average visibility in September
Mount Pleasant, 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).
