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 beginning of September subtly marks a decrease in the average high-temperature, transitioning from a hot 90.1°F (32.3°C) in August to a moderately hot 84.6°F (29.2°C). An average low-temperature of 64.9°F (18.3°C) is observed during September nights.Heat index
During September, the heat index is computed to be a hot 93.2°F (34°C). Implement more safety precautions, heat cramps and heat exhaustion may happen. Persistent activity could induce heatstroke.The heat index's values are generally associated with conditions in shade and light breezes. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', marries air temperature and humidity to produce a value illustrating perceived warmth. This effect tends to be personal, with the weather perception differing among individuals due to variations in body mass, height, and exertion. Awareness is key; direct sunlight can enhance the weather's impact, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Young individuals are generally in more danger than adults due to their lower capacity to sweat. Moreover, their large skin surface in relation to their small bodies and the increased heat generation from their activities makes them more vulnerable.
Humidity
In Iris, the average relative humidity in September is 72%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.8 days and typically collects 1.61" (41mm) of precipitation.Snowfall
April through November are months without snowfall.Daylight
In Iris, 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 7:23 am and sunset at 7:14 pm EDT.
Sunshine
In Iris, the average sunshine in September is 8.5h.UV index
In September, the average daily maximum UV index is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: The daily high UV index of 6 during September translates into the following recommendations:
Resist overexposure. Safeguarding from solar damage is indispensable. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
What is the average humidity in September?
What is the driest month?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September in Iris?
What time are sunrise and sunset in September in Iris?
How many hours of sunshine does Iris have in September?
How high is the UV index in September?
Average temperature in September
Iris, SC
- Average high temperature in September: 84.6°F
The warmest month (with the highest average high temperature) is July (91.9°F).
The month with the lowest average high temperature is January (51.6°F).
- Average low temperature in September: 64.9°F
The month with the highest average low temperature is July (70.7°F).
The coldest month (with the lowest average low temperature) is January (35.2°F).
Average pressure in September
Iris, 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
Iris, SC
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is February (7.3mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in September
Iris, 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
Iris, SC
- Average rainfall in September: 1.61"
The wettest month (with the highest rainfall) is December (3.74").
The driest month (with the least rainfall) is September (1.61").
Average rainfall days in September
Iris, SC
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is October (9.1 days).
Average snowfall in September
Iris, SC
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.94").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Iris, SC
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.8 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
Iris, 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 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 18min).
Average sunshine days in September
Iris, SC
- Average sunshine days in September: 17 days
The month with the most sunshine days is October (20.8 days).
The month with the least sunshine days is July (10.3 days).
Average UV index in September
Iris, SC
- Average UV index in September: 6
The months with the highest UV index are June and August (UV index 7).
The month with the lowest UV index is January (UV index 2).
Average cloud cover in September
Iris, SC
- Average cloud cover in September: 30
The months with the most cloud cover are February and December (Cloud cover 42).
The months with the least cloud cover are June and October (Cloud cover 29).
Average visibility in September
Iris, 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).
Iris, South Carolina, USA
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