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 transition into September is accompanied by a slight temperature decrease, with the average high-temperature shifting from a moderately hot 83.3°F (28.5°C) in August to a still warm 76.1°F (24.5°C). Irene reports an average nighttime low-temperature of 55°F (12.8°C) in September.Humidity
In September, the average relative humidity is 67%.Rainfall
In Irene, South Dakota, during September, the rain falls for 11.6 days and regularly aggregates up to 1.81" (46mm) of precipitation. In Irene, during the entire year, the rain falls for 117.9 days and collects up to 21.93" (557mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:53 am and sunset at 8:02 pm. On the last day of September, sunrise is at 7:25 am and sunset at 7:11 pm CDT.
Sunshine
In September, the average sunshine in Irene is 8.8h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: During September, 5 as the daily maximum UV index converts into the following advice:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. When the Sun is at its strongest around midday, find shade and limit exposure. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Irene in September?
What is the average humidity in September in Irene?
How much does it rain in Irene in September?
When it does not snow in Irene?
Does it snow in Irene in September?
What is the average length of the day in September in Irene?
When is the sunrise / sunset in September in Irene?
How long on average sun shines in September in Irene?
What is the UV index reading in September in Irene?
Average temperature in September
Irene, SD
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (26.8°F).
- Average low temperature in September: 55°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (12.9°F).
Average pressure in September
Irene, SD
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Irene, SD
- Average wind speed in September: 9.2mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.9mph).
Average humidity in September
Irene, SD
- Average humidity in September: 67%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is October (64%).
Average rainfall in September
Irene, SD
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is May (3.78").
The driest month (with the least rainfall) is February (0.59").
Average rainfall days in September
Irene, SD
- Average rainfall days in September: 11.6 days
The month with the highest number of rainy days is June (17.4 days).
The month with the least rainy days is February (2.3 days).
Average snowfall in September
Irene, SD
- Average snowfall in September: 0"
The month with the highest snowfall is December (2.95").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Irene, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Irene, SD
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in September
Irene, SD
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is June (9.3 days).
Average UV index in September
Irene, SD
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Irene, SD
- Average cloud cover in September: 26
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 25).
Average visibility in September
Irene, SD
- 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).
Irene, South Dakota, USA
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