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 advent of September brings a subtle shift in temperature, with the average high moving from a moderately hot 84.2°F (29°C) in August to a still warm 75.7°F (24.3°C). Nighttime temperature in Iroquois dips to a mean of 54.5°F (12.5°C) during September.Humidity
The least humid month is September, with an average relative humidity of 62%.Rainfall
In Iroquois, in September, during 9.8 rainfall days, 1.38" (35mm) of precipitation is typically accumulated. Throughout the year, there are 101.8 rainfall days, and 18.19" (462mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall in Iroquois.Daylight
In Iroquois, South Dakota, the average length of the day in September is 12h and 30min.On the first day of September in Iroquois, sunrise is at 6:55 am and sunset at 8:07 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 7:13 pm CDT.
Sunshine
In Iroquois, the average sunshine in September is 8.9h.UV index
In Iroquois, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Frequently asked questions
What is the usual temperature for Iroquois in September?
What is the least humid month in Iroquois?
What is the average humidity in September in Iroquois?
How much does it rain in Iroquois in September?
When it does not snow in Iroquois?
Does it snow in Iroquois in September?
How many hours of daylight does Iroquois have in September?
When is the sunrise / sunset in September in Iroquois?
How many hours of sunshine does Iroquois have in September?
What is the UV index intensity in September in Iroquois?
Average temperature in September
Iroquois, SD
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (23.2°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (8.2°F).
Average pressure in September
Iroquois, SD
- Average pressure in September: 29.96"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Iroquois, SD
- Average wind speed in September: 9.7mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest months (with the lowest average wind speed) are July and August (8.6mph).
Average humidity in September
Iroquois, SD
- Average humidity in September: 62%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is September (62%).
Average rainfall in September
Iroquois, SD
- Average rainfall in September: 1.38"
The wettest month (with the highest rainfall) is June (2.8").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in September
Iroquois, SD
- Average rainfall days in September: 9.8 days
The month with the highest number of rainy days is June (15.2 days).
The month with the least rainy days is February (1.8 days).
Average snowfall in September
Iroquois, SD
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.54").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Iroquois, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (9.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Iroquois, SD
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Iroquois, SD
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is November (21.8 days).
The month with the least sunshine days is June (12.3 days).
Average UV index in September
Iroquois, SD
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January and November (UV index 1).
Average cloud cover in September
Iroquois, SD
- Average cloud cover in September: 26
The month with the most cloud cover is January (Cloud cover 54).
The month with the least cloud cover is July (Cloud cover 22).
Average visibility in September
Iroquois, SD
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Iroquois, South Dakota, USA
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