September weather forecastInterior, SD
September
Weather in September
September, the first month of the autumn in Interior, is also a moderately hot month, with an average temperature fluctuating between 77.5°F (25.3°C) and 58.3°F (14.6°C).Temperature
Interior's progression into September includes a drop in the average high-temperature, from a hot 87.1°F (30.6°C) in August to a moderately hot 77.5°F (25.3°C). Throughout September, an average nighttime temperature of 58.3°F (14.6°C) is experienced in Interior, South Dakota.Humidity
With an average relative humidity of 47%, September is the least humid month.Rainfall
In Interior, South Dakota, in September, during 8.5 rainfall days, 0.91" (23mm) of precipitation is typically accumulated. In Interior, during the entire year, the rain falls for 95.3 days and collects up to 13.74" (349mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Interior, South Dakota, the average length of the day in September is 12h and 29min.On the first day of September in Interior, South Dakota, sunrise is at 6:12 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:30 pm MDT.
Sunshine
In Interior, the average sunshine in September is 9.9h.UV index
In Interior, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: The average daily UV index of 5 in September transforms into the following instructions:
Heed the precautions - Suggestions to avoid sunburn are made. The solar radiation around mid-day is intense; avoid the Sun and stay safe. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Interior, SD
- Average high temperature in September: 77.5°F
The warmest month (with the highest average high temperature) is July (89.2°F).
The month with the lowest average high temperature is January (29.8°F).
- Average low temperature in September: 58.3°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (16.7°F).
Average pressure in September
Interior, SD
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Interior, SD
- Average wind speed in September: 11.1mph
The windiest month (with the highest average wind speed) is April (12.1mph).
The calmest month (with the lowest average wind speed) is February (10.1mph).
Average humidity in September
Interior, SD
- Average humidity in September: 47%
The month with the highest relative humidity is January (81%).
The month with the lowest relative humidity is September (47%).
Average rainfall in September
Interior, SD
- Average rainfall in September: 0.91"
The wettest month (with the highest rainfall) is May (2.09").
The driest month (with the least rainfall) is January (0.39").
Average rainfall days in September
Interior, SD
- Average rainfall days in September: 8.5 days
The month with the highest number of rainy days is May (13.5 days).
The month with the least rainy days is February (2.6 days).
Average snowfall in September
Interior, SD
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.15").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Interior, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (8.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Interior, SD
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 9h and 54min
The month with the most sunshine is August (Average sunshine: 11h and 42min).
The months with the least sunshine are January and February (Average sunshine: 5h and 12min).
Average sunshine days in September
Interior, SD
- Average sunshine days in September: 18.8 days
The month with the most sunshine days is December (21.1 days).
The months with the least sunshine days are April and June (14.1 days).
Average UV index in September
Interior, SD
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Interior, SD
- Average cloud cover in September: 19
The month with the most cloud cover is January (Cloud cover 46).
The months with the least cloud cover are July and August (Cloud cover 18).
Average visibility in September
Interior, 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).
