September weather forecast
Yankton, SD

Weather in September

September, the first month of the autumn in Yankton, is also a moderately hot month, with temperature in the range of an average high of 76.1°F (24.5°C) and an average low of 55°F (12.8°C).

Temperature

In September, the average high-temperature slightly decreases from a moderately hot 83.3°F (28.5°C) in August to a still warm 76.1°F (24.5°C). In September, the average low-temperature is 55°F (12.8°C).

Humidity

In Yankton, South Dakota, the average relative humidity in September is 67%.

Rainfall

In Yankton, in September, it is raining for 11.6 days, with typically 1.81" (46mm) of accumulated precipitation. In Yankton, during the entire year, the rain falls for 117.9 days and collects up to 21.93" (557mm) of precipitation.

Snowfall

In Yankton, snow does not fall in June through September.

Daylight

In Yankton, the average length of the day in September is 12h and 29min.
On the first day of September, sunrise is at 6:54 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 7:13 pm CDT.

Sunshine

In Yankton, South Dakota, the average sunshine in September is 8.8h.

UV index

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the ordinary person.
Note: The daily maximum UV index of 5 in September interpret into the following advice:
Take precautions - Protection against sunburn is recommended. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the temperature in September in Yankton?

The average high-temperature, in September, in Yankton, is 76.1°F (24.5°C), while the average low-temperature is 55°F (12.8°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which factors the actual air temperature with the relative humidity, in August is appraised at 89.6°F (32°C).

What is the average humidity in September in Yankton?

The average relative humidity in September is 67%.

How many days does it rain in September in Yankton?

In September, in Yankton, the rain falls for 11.6 days. Throughout September, 1.81" (46mm) of precipitation is accumulated.

When it does not snow in Yankton?

June through September are months without snowfall in Yankton, South Dakota.

Does it snow in Yankton in September?

In Yankton, South Dakota, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Yankton have in September?

In Yankton, South Dakota, the average day length in September is 12h and 29min.

What time are sunrise and sunset in September in Yankton?

On the first day of September in Yankton, South Dakota, sunrise is at 6:54 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 7:13 pm CDT.

How long on average sun shines in September in Yankton?

The average sunshine duration in September in Yankton is 8.8h.

What is the UV index intensity in September in Yankton?

The average daily maximum UV index in September in Yankton is 5. A UV Index of 3 to 5 symbolizes a moderate health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Yankton, SD

Average temperature in September - Yankton, 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).

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Average pressure in September
Yankton, SD

Average pressure in September - Yankton, 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).

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Average wind speed in September
Yankton, SD

Average wind speed in September - Yankton, 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).

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Average humidity in September
Yankton, SD

Average humidity in September - Yankton, 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%).

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Average rainfall in September
Yankton, SD

Average rainfall in September - Yankton, 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").

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Average rainfall days in September
Yankton, SD

Average rainfall days in September - Yankton, 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).

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Average snowfall in September
Yankton, SD

Average snowfall in September - Yankton, 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").

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Average snowfall days in September
Yankton, SD

Average snowfall days in September - Yankton, 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).

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Average daylight in September /
Average sunshine in September
Yankton, SD

Average daylight in September / Average sunshine in September - Yankton, SD
  • Average daylight in September: 12h and 29min

The month with the longest days is June (Average daylight: 15h and 17min).
The month with the shortest days is December (Average daylight: 9h and 5min).

  • Average sunshine in September: 8h and 48min

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).

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Average sunshine days in September
Yankton, SD

Average sunshine days in September - Yankton, 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).

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Average UV index in September
Yankton, SD

Average UV index in September - Yankton, 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).

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Average cloud cover in September
Yankton, SD

Average cloud cover in September - Yankton, 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).

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Average visibility in September
Yankton, SD

Average visibility in September - Yankton, 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).

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