September weather forecastIrwin, SC
September
Weather in September
September, the first month of the autumn in Irwin, is also a moderately hot month, with an average temperature varying between 64.9°F (18.3°C) and 82.9°F (28.3°C).Temperature
With the onset of September, Irwin's average high-temperature slightly adjusts, moderately receding from August's tropical 88.3°F (31.3°C) to a moderately hot 82.9°F (28.3°C). Nighttime temperatures hover around an average low of 64.9°F (18.3°C) in September.Heat index
For September, the heat index is calculated to be a tropical 89.6°F (32°C). Fatigue might occur with continuous exposure and activity, potentially causing heat cramps.The heat index's values are generally associated with conditions in shade and light breezes. The heat index could experience an increase of 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'real feel' or 'apparent temperature', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Direct sunlight can potentially raise the heat index by 15 Fahrenheit (8 Celsius) degrees, so it's crucial to consider. Heat index values are particularly meaningful for babies and toddlers. Youngsters typically face more danger than adults since they sweat less. Their larger skin surface compared to their small bodies and heightened heat production from their activities augment their vulnerability.
Humidity
In September, the average relative humidity is 73%.Rainfall
The month with the least rainfall is September, when the rain falls for 9.6 days and typically collects 0.51" (13mm) of precipitation.Snowfall
In Irwin, snow does not fall in March through December.Daylight
In September, the average length of the day is 12h and 23min.On the first day of September, sunrise is at 6:56 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:17 am and sunset at 7:08 pm EDT.
Sunshine
In September, the average sunshine is 8.9h.UV index
In Irwin, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for the average person.Note: A daily maximum UV index of 6 in September translates into the following instructions:
Act on precautions and pay attention to sun safety recommendations. Avoidance of sunburn is obligatory. 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. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Irwin, SC
- Average high temperature in September: 82.9°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 (49.8°F).
- Average low temperature in September: 64.9°F
The month with the highest average low temperature is July (71.2°F).
The coldest month (with the lowest average low temperature) is January (35.2°F).
Average pressure in September
Irwin, 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 (29.97"Hg).
Average wind speed in September
Irwin, SC
- Average wind speed in September: 5.5mph
The windiest months (with the highest average wind speed) are February and April (8mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Irwin, SC
- Average humidity in September: 73%
The months with the highest relative humidity are May and December (75%).
The months with the lowest relative humidity are June, July and November (71%).
Average rainfall in September
Irwin, SC
- Average rainfall in September: 0.51"
The wettest month (with the highest rainfall) is August (1.61").
The driest month (with the least rainfall) is September (0.51").
Average rainfall days in September
Irwin, SC
- Average rainfall days in September: 9.6 days
The month with the highest number of rainy days is July (14.9 days).
The month with the least rainy days is November (5.9 days).
Average snowfall in September
Irwin, SC
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.12").
The months with the least snowfall are March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Irwin, SC
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.5 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
Irwin, SC
- Average daylight in September: 12h and 24min
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 54min
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 30min).
Average sunshine days in September
Irwin, SC
- Average sunshine days in September: 18.3 days
The month with the most sunshine days is October (23.5 days).
The month with the least sunshine days is July (12.9 days).
Average UV index in September
Irwin, SC
- Average UV index in September: 6
The months with the highest UV index are June and July (UV index 7).
The month with the lowest UV index is January (UV index 2).
Average cloud cover in September
Irwin, SC
- Average cloud cover in September: 31
The month with the most cloud cover is February (Cloud cover 42).
The month with the least cloud cover is June (Cloud cover 28).
Average visibility in September
Irwin, 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).
