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
Vivian's September weather shows a moderate shift in high-temperatures, falling from August's tropical 86°F (30°C) to a warm 76.8°F (24.9°C). September brings with it a nighttime average temperature of 57.4°F (14.1°C).Humidity
The months with the lowest humidity in Vivian are August and September, with an average relative humidity of 52%.Rainfall
In Vivian, in September, during 8.9 rainfall days, 0.67" (17mm) of precipitation is typically accumulated. In Vivian, during the entire year, the rain falls for 98.5 days and collects up to 13.7" (348mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 29min.On the first day of September, sunrise is at 7:05 am and sunset at 8:16 pm. On the last day of the month, sunrise is at 7:38 am and sunset at 7:23 pm CDT.
Sunshine
The average sunshine in September is 9h.UV index
In Vivian, South Dakota, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index, 5 during September, leads to the following recommendations:
Ensure safety - Imperative it is to shield skin and eyes from damage. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the least humid month?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in Vivian in September?
How many hours of daylight does Vivian have in September?
When are sunrise and sunset in September?
How many hours of sunshine does Vivian have in September?
How high is the UV index in September?
Average temperature in September
Vivian, SD
- Average high temperature in September: 76.8°F
The warmest month (with the highest average high temperature) is July (88.7°F).
The month with the lowest average high temperature is January (26.2°F).
- Average low temperature in September: 57.4°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (12.6°F).
Average pressure in September
Vivian, SD
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Vivian, SD
- Average wind speed in September: 11.1mph
The windiest month (with the highest average wind speed) is April (11.9mph).
The calmest months (with the lowest average wind speed) are February and August (9.9mph).
Average humidity in September
Vivian, SD
- Average humidity in September: 52%
The month with the highest relative humidity is January (85%).
The months with the lowest relative humidity are August and September (52%).
Average rainfall in September
Vivian, SD
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is May (2.24").
The driest month (with the least rainfall) is January (0.35").
Average rainfall days in September
Vivian, SD
- Average rainfall days in September: 8.9 days
The month with the highest number of rainy days is June (14.2 days).
The month with the least rainy days is February (2.4 days).
Average snowfall in September
Vivian, SD
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.66").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Vivian, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (10 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Vivian, 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: 9h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in September
Vivian, SD
- Average sunshine days in September: 18.8 days
The month with the most sunshine days is November (22.3 days).
The month with the least sunshine days is June (13.7 days).
Average UV index in September
Vivian, SD
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are February and December (UV index 1).
Average cloud cover in September
Vivian, SD
- Average cloud cover in September: 21
The month with the most cloud cover is January (Cloud cover 50).
The months with the least cloud cover are July and August (Cloud cover 19).
Average visibility in September
Vivian, 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).
Vivian, South Dakota, USA
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