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
With September's onset, the weather reveals a slight temperature decrease, transitioning from 84.6°F (29.2°C) in August to a still warm 75.7°F (24.3°C). In September, Mission experiences an average nighttime temperature of 55.8°F (13.2°C).Humidity
With an average relative humidity of 56%, September is the least humid month.Rainfall
In Mission, in September, it is raining for 10.2 days, with typically 1.14" (29mm) of accumulated precipitation. In Mission, during the entire year, the rain falls for 109.2 days and collects up to 16.89" (429mm) of precipitation.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.2" (5mm) of snow. Throughout the year, there are 41.1 snowfall days, and 14.53" (369mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 7:07 am and sunset at 8:17 pm. On the last day of September, sunrise is at 7:39 am and sunset at 7:24 pm CDT.
Sunshine
In Mission, the average sunshine in September is 9.1h.UV index
In September, the average daily maximum UV index in Mission is 5. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: In September, the maximum UV index of 5 suggests these recommendations:
Guard yourself - An obligation to protect skin and eyes from harm exists. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Remember! The Sun's UV radiation can be magnified almost twofold by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the least humid month?
What is the average humidity in September?
How many days does it rain in September?
When does it start snowing?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Mission have in September?
What is the UV index reading in September?
Average temperature in September
Mission, SD
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (31.5°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).
Average pressure in September
Mission, SD
- Average pressure in September: 29.95"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
Mission, SD
- Average wind speed in September: 11.7mph
The windiest month (with the highest average wind speed) is April (13.1mph).
The calmest months (with the lowest average wind speed) are July and August (10.6mph).
Average humidity in September
Mission, SD
- Average humidity in September: 56%
The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is September (56%).
Average rainfall in September
Mission, SD
- Average rainfall in September: 1.14"
The wettest month (with the highest rainfall) is May (2.6").
The driest month (with the least rainfall) is January (0.47").
Average rainfall days in September
Mission, SD
- Average rainfall days in September: 10.2 days
The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is January (2.4 days).
Average snowfall in September
Mission, SD
- Average snowfall in September: 0.2"
The month with the highest snowfall is December (2.76").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Mission, SD
- Average snowfall days in September: 0.1 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 and August (0 days).
Average daylight in September /
Average sunshine in September
Mission, 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 0min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is January (Average sunshine: 5h and 24min).
Average sunshine days in September
Mission, SD
- Average sunshine days in September: 17.2 days
The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is June (11.2 days).
Average UV index in September
Mission, SD
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Mission, SD
- Average cloud cover in September: 21
The month with the most cloud cover is February (Cloud cover 44).
The months with the least cloud cover are July, August and September (Cloud cover 21).
Average visibility in September
Mission, 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).
Mission, South Dakota, USA
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