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
September
Weather in September
Temperature
September brings a slight decrease in the average high-temperature, shifting from 83.3°F (28.5°C) in August to a still moderately hot 76.1°F (24.5°C). In September, the average low-temperature records at a cool 55°F (12.8°C) during the nights.Humidity
In Yankton, South Dakota, the average relative humidity in September is 67%.Rainfall
In September, the rain falls for 11.6 days. Throughout September, 1.81" (46mm) of precipitation is accumulated. Throughout the year, in Yankton, South Dakota, there are 117.9 rainfall days, and 21.93" (557mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Yankton, the average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:55 am and sunset at 8:03 pm. On the last day of September, in Yankton, sunrise is at 7:26 am and sunset at 7:12 pm CDT.
Sunshine
In September, the average sunshine in Yankton is 8.8h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: A daily high UV index of 5 in September leads to these guidelines:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Yankton?
What is the average humidity in September in Yankton?
How much does it rain in Yankton in September?
When it does not snow in Yankton?
Does it snow in Yankton in September?
How many hours of daylight does Yankton have in September?
When is the sunrise / sunset in September in Yankton?
How long on average sun shines in September in Yankton?
What is the UV index intensity in September in Yankton?
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).
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).
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).
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%).
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").
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).
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").
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).
Average daylight in September /
Average sunshine in September
Yankton, 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
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).
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).
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).
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).