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 results in a small decrease in the average high-temperature, moderately receding from a tropical 88.9°F (31.6°C) in August to a moderately hot 83.5°F (28.6°C). The average temperature in Williamston drops to a refreshing 63.5°F (17.5°C) during the night in the month of September.Heat index
For September, the heat index is computed to be a tropical 89.6°F (32°C). Persisting in activity during exposure could lead to weariness and subsequently to heat cramps.When considering the heat index, it's pivotal to note it is for shade and mild wind conditions. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is a metric representing the sensation of warmth when air temperature and moisture come together. One's weather perception can be influenced by a range of factors including metabolic differences, being pregnant, and their level of physical activity. 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 essentially critical for children. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.
Humidity
In Williamston, the average relative humidity in September is 72%.Rainfall
The month with the least rainfall in Williamston, South Carolina, is September, when the rain falls for 11.7 days and typically collects 1.81" (46mm) of precipitation.Snowfall
In Williamston, snow does not fall in April through October.Daylight
In Williamston, South Carolina, the average length of the day in September is 12h and 23min.On the first day of September, sunrise is at 7:03 am and sunset at 7:55 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:14 pm EDT.
Sunshine
In Williamston, the average sunshine in September is 8.3h.UV index
In September, the average daily maximum UV index in Williamston is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum UV index of 5 during September leads to these instructions:
Act with care - Obligation to protect against skin and eye damage is highlighted. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Frequently asked questions
How hot is September in Williamston?
What is the average humidity in September in Williamston?
What is the driest month in Williamston?
How many days does it rain in September in Williamston?
When it does not snow in Williamston?
What is the average length of the day in September in Williamston?
What time are sunrise and sunset in September in Williamston?
How long on average sun shines in September in Williamston?
What is the UV index reading in September in Williamston?
Average temperature in September
Williamston, SC
- Average high temperature in September: 83.5°F
The warmest month (with the highest average high temperature) is July (90.3°F).
The month with the lowest average high temperature is January (50°F).
- Average low temperature in September: 63.5°F
The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (34.5°F).
Average pressure in September
Williamston, SC
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in September
Williamston, SC
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is February (7.2mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in September
Williamston, SC
- Average humidity in September: 72%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is July (70%).
Average rainfall in September
Williamston, SC
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is May (4.09").
The driest month (with the least rainfall) is September (1.81").
Average rainfall days in September
Williamston, SC
- Average rainfall days in September: 11.7 days
The month with the highest number of rainy days is July (17.7 days).
The month with the least rainy days is October (8.5 days).
Average snowfall in September
Williamston, SC
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.1").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Williamston, SC
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.3 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Williamston, SC
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).
Average sunshine days in September
Williamston, SC
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is October (21.5 days).
The month with the least sunshine days is July (11.5 days).
Average UV index in September
Williamston, SC
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 2).
Average cloud cover in September
Williamston, SC
- Average cloud cover in September: 33
The months with the most cloud cover are February and December (Cloud cover 45).
The month with the least cloud cover is June (Cloud cover 30).
Average visibility in September
Williamston, SC
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
Williamston, South Carolina, USA
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