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
An average high-temperature of a moderately hot 84°F (28.9°C) marks September, exhibiting a close resemblance to the conditions in August. Throughout September, Williston encounters an average temperature drop to an enjoyable 67.6°F (19.8°C).Heat index
For most parts of September, the heat index is appraised at a hot 91.4°F (33°C). Additional precautions are required to avert heat cramps and heat exhaustion. Persistent activity may culminate in heatstroke.Heat index values are typically calculated for conditions of shade and a light breeze. Direct sunlight can cause a surge in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is achieved by amalgamating air temperature with the relative humidity readings. The influence of weather is personal, differing among a variety of individuals based on differences in body mass, stature, and the level of physical activity. Consider the fact that direct sun exposure can influence how hot one feels, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Children often overlook the necessity for resting and fluid replenishment. Thirst is a late sign of dehydration - thus, it is critical to stay hydrated, especially during extended periods of physical activities.
Humidity
In September, the average relative humidity is 74%.Rainfall
In Williston, in September, during 12.7 rainfall days, 1.85" (47mm) of precipitation is typically accumulated. In Williston, during the entire year, the rain falls for 157.7 days and collects up to 30.2" (767mm) of precipitation.Snowfall
March through November are months without snowfall.Daylight
In September, the average length of the day is 12h and 22min.On the first day of the month, sunrise is at 7:00 am and sunset at 7:50 pm. On the last day of September, in Williston, South Carolina, sunrise is at 7:19 am and sunset at 7:11 pm EDT.
Sunshine
In Williston, South Carolina, the average sunshine in September is 8.5h.UV index
In September, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for average individuals.Note: A maximum high UV index of 6 in September translates into the following recommendations:
Endorse precautions and be consistent with sun safety guidelines. Preventing sunburn is paramount. To the best of your ability, limit your exposure to the sun between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Frequently asked questions
How hot does it get in Williston in September?
What is the average humidity in September in Williston?
How many days does it rain in September in Williston?
When it does not snow in Williston?
How many hours of daylight does Williston have in September?
What time are sunrise and sunset in September in Williston?
How many hours of sunshine does Williston have in September?
What is the UV index reading in September in Williston?
Average temperature in September
Williston, SC
- Average high temperature in September: 84°F
The warmest month (with the highest average high temperature) is July (90.5°F).
The month with the lowest average high temperature is January (54°F).
- Average low temperature in September: 67.6°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 (38.8°F).
Average pressure in September
Williston, SC
- Average pressure in September: 30.01"Hg
The months with the highest atmospheric pressure are January, November and December (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.97"Hg).
Average wind speed in September
Williston, SC
- Average wind speed in September: 6.4mph
The windiest months (with the highest average wind speed) are February, March and April (8.6mph).
The calmest month (with the lowest average wind speed) is August (5.8mph).
Average humidity in September
Williston, SC
- Average humidity in September: 74%
The month with the highest relative humidity is December (75%).
The months with the lowest relative humidity are January and November (70%).
Average rainfall in September
Williston, SC
- Average rainfall in September: 1.85"
The wettest month (with the highest rainfall) is December (3.35").
The driest month (with the least rainfall) is November (1.77").
Average rainfall days in September
Williston, SC
- Average rainfall days in September: 12.7 days
The month with the highest number of rainy days is July (19 days).
The month with the least rainy days is November (8.2 days).
Average snowfall in September
Williston, SC
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.31").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Williston, SC
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.6 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Williston, 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 3min
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 24min).
Average sunshine days in September
Williston, SC
- Average sunshine days in September: 14.7 days
The month with the most sunshine days is October (20.5 days).
The month with the least sunshine days is July (9.4 days).
Average UV index in September
Williston, SC
- Average UV index in September: 6
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January and December (UV index 3).
Average cloud cover in September
Williston, SC
- Average cloud cover in September: 31
The month with the most cloud cover is December (Cloud cover 42).
The month with the least cloud cover is October (Cloud cover 28).
Average visibility in September
Williston, 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).
Williston, South Carolina, USA
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