September weather forecastLyman, SC
September
Weather in September
September, the first month of the autumn in Lyman, is also a moderately hot month, with an average temperature ranging between max 83.7°F (28.7°C) and min 62.8°F (17.1°C).Temperature
As September commences, the average high-temperature subtly reduces, transitioning from a tropical 89.2°F (31.8°C) in August to a warm 83.7°F (28.7°C). Lyman experiences a consistent average temperature of 62.8°F (17.1°C) throughout the nights in September.Heat index
The heat index value during September is estimated at a tropical 89.6°F (32°C). With sustained exposure and activity, exhaustion becomes probable, resulting in heat cramps.When considering the heat index, it's pivotal to note it is for shade and mild wind conditions. The heat index could experience an increase of 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a numerical representation of warmth when taking temperature and moisture levels into account. The individual's impression of temperature can be affected by numerous factors such as metabolic variations, physical exertion, and attire. Given the impact of direct sunlight, it's noteworthy that the felt temperature can rise by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Young ones are generally at greater risk than adults due to their limited sweating ability. In addition, their large skin surface relative to their small bodies and higher heat production from their activities add to their vulnerability.
Humidity
The average relative humidity in September is 71%.Rainfall
September is the month with the least rainfall. Rain falls for 11.2 days and accumulates 1.38" (35mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In Lyman, the average length of the day in September is 12h and 23min.On the first day of the month, sunrise is at 7:01 am and sunset at 7:54 pm. On the last day of September, sunrise is at 7:23 am and sunset at 7:13 pm EDT.
Sunshine
In September, the average sunshine in Lyman is 8.4h.UV index
The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 5 translates into these guidelines:
Prioritize safety - Recommendations to avert sunburn are shared. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Lyman, SC
- Average high temperature in September: 83.7°F
The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is January (48.9°F).
- Average low temperature in September: 62.8°F
The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is January (32.9°F).
Average pressure in September
Lyman, SC
- Average pressure in September: 30.04"Hg
The month with the highest atmospheric pressure is November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.99"Hg).
Average wind speed in September
Lyman, SC
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is April (7mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).
Average humidity in September
Lyman, SC
- Average humidity in September: 71%
The month with the highest relative humidity is December (76%).
The month with the lowest relative humidity is July (67%).
Average rainfall in September
Lyman, SC
- Average rainfall in September: 1.38"
The wettest month (with the highest rainfall) is December (3.35").
The driest month (with the least rainfall) is September (1.38").
Average rainfall days in September
Lyman, SC
- Average rainfall days in September: 11.2 days
The month with the highest number of rainy days is July (15.3 days).
The month with the least rainy days is November (8.2 days).
Average snowfall in September
Lyman, SC
- Average snowfall in September: 0"
The month with the highest snowfall is December (2.2").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Lyman, SC
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.6 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
Lyman, SC
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 8h and 24min
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 18min).
Average sunshine days in September
Lyman, SC
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is October (22.3 days).
The month with the least sunshine days is August (13.3 days).
Average UV index in September
Lyman, SC
- 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
Lyman, SC
- Average cloud cover in September: 32
The month with the most cloud cover is December (Cloud cover 43).
The months with the least cloud cover are June and July (Cloud cover 28).
Average visibility in September
Lyman, 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).





