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
The beginning of September brings a slight decrease in the average high-temperature, transitioning from a warm 80.1°F (26.7°C) in August to an agreeable 71.6°F (22°C). Willow Lake sees an average low-temperature of 51.3°F (10.7°C) during September.Humidity
The months with the lowest humidity are September and October, with an average relative humidity of 68%.Rainfall
In September, the rain falls for 10.4 days. Throughout September, 1.57" (40mm) of precipitation is accumulated. Throughout the year, there are 112.3 rainfall days, and 18.78" (477mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall in Willow Lake.Daylight
In September, the average length of the day is 12h and 30min.On the first day of September, sunrise is at 6:53 am and sunset at 8:06 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 7:12 pm CDT.
Sunshine
The average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 4 during September leads to these advisories:
Act with care - Obligation to protect against skin and eye damage is highlighted. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the least humid month?
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 Willow Lake?
How many hours of sunshine does Willow Lake have in September?
What is the UV index reading in September?
Average temperature in September
Willow Lake, SD
- Average high temperature in September: 71.6°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (19.4°F).
- Average low temperature in September: 51.3°F
The month with the highest average low temperature is July (60.8°F).
The coldest month (with the lowest average low temperature) is January (5.5°F).
Average pressure in September
Willow Lake, SD
- Average pressure in September: 29.97"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Willow Lake, SD
- Average wind speed in September: 10mph
The windiest month (with the highest average wind speed) is April (11.6mph).
The calmest month (with the lowest average wind speed) is July (8.5mph).
Average humidity in September
Willow Lake, SD
- Average humidity in September: 68%
The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are September and October (68%).
Average rainfall in September
Willow Lake, SD
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is June (3.19").
The driest months (with the least rainfall) are January and February (0.59").
Average rainfall days in September
Willow Lake, SD
- Average rainfall days in September: 10.4 days
The month with the highest number of rainy days is June (17.2 days).
The month with the least rainy days is February (2.7 days).
Average snowfall in September
Willow Lake, SD
- Average snowfall in September: 0"
The months with the highest snowfall are January and December (3.74").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Willow Lake, SD
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (14.4 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Willow Lake, SD
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Willow Lake, SD
- Average sunshine days in September: 18.2 days
The month with the most sunshine days is October (19.1 days).
The month with the least sunshine days is June (10.3 days).
Average UV index in September
Willow Lake, 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 and December (UV index 1).
Average cloud cover in September
Willow Lake, SD
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Willow Lake, 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).
Willow Lake, South Dakota, USA
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