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
A modest decline in the average high-temperature is seen during September, decreasing from a moderately hot 79.9°F (26.6°C) in August to a pleasant 72.5°F (22.5°C). During September, Flandreau's temperature averages to a cool 52.3°F (11.3°C) at night.Humidity
In Flandreau, the average relative humidity in September is 70%.Rainfall
In September, the rain falls for 10.2 days. Throughout September, 1.61" (41mm) of precipitation is accumulated. In Flandreau, during the entire year, the rain falls for 113.8 days and collects up to 20.59" (523mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:50 am and sunset at 8:01 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 7:08 pm CDT.
Sunshine
The average sunshine in September in Flandreau is 8.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: A daily high UV index of 4 in September leads to these guidelines:
Ensure safety - Sun damage prevention is strongly urged. To protect against the Sun's most potent rays, avoid direct exposure around midday. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
When is the sunrise / sunset in September in Flandreau?
How long on average sun shines in September in Flandreau?
How high is the UV index in September in Flandreau?
Average temperature in September
Flandreau, SD
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (21.6°F).
- Average low temperature in September: 52.3°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (7.7°F).
Average pressure in September
Flandreau, SD
- Average pressure in September: 29.98"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in September
Flandreau, SD
- Average wind speed in September: 9.8mph
The windiest month (with the highest average wind speed) is April (11.6mph).
The calmest month (with the lowest average wind speed) is July (8.3mph).
Average humidity in September
Flandreau, SD
- Average humidity in September: 70%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (68%).
Average rainfall in September
Flandreau, SD
- Average rainfall in September: 1.61"
The wettest month (with the highest rainfall) is June (3.15").
The driest months (with the least rainfall) are January and November (0.63").
Average rainfall days in September
Flandreau, SD
- Average rainfall days in September: 10.2 days
The month with the highest number of rainy days is June (17.6 days).
The month with the least rainy days is February (2.4 days).
Average snowfall in September
Flandreau, SD
- Average snowfall in September: 0"
The month with the highest snowfall is December (4.8").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Flandreau, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Flandreau, SD
- Average daylight in September: 12h and 3min
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: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Flandreau, SD
- Average sunshine days in September: 17.6 days
The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is June (10.3 days).
Average UV index in September
Flandreau, SD
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
Flandreau, SD
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in September
Flandreau, 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).
Flandreau, South Dakota, USA
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