September weather forecastBig Flats, WI
September
Weather in September
September, the first month of the autumn in Big Flats, is also an agreeable month, with temperature in the range of an average low of 52°F (11.1°C) and an average high of 70.3°F (21.3°C).Temperature
September marks a gentle change in average high-temperature, declining from August's warm 77.5°F (25.3°C) to a pleasant 70.3°F (21.3°C). September nights are marked by an average temperature drop to a cool 52°F (11.1°C).Humidity
The average relative humidity in September is 79%.Rainfall
In September, the rain falls for 11.4 days. Throughout September, 2.24" (57mm) of precipitation is accumulated. Throughout the year, there are 129.4 rainfall days, and 26.3" (668mm) of precipitation is accumulated.Snowfall
In Big Flats, snow does not fall in June through September.Daylight
In Big Flats, Wisconsin, the average length of the day in September is 12h and 30min.On the first day of the month, sunrise is at 6:23 am and sunset at 7:34 pm. On the last day of September, sunrise is at 6:56 am and sunset at 6:41 pm CDT.
Sunshine
The average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 3 during September translates into the following directions:
Take necessary precautions - Defending against sun damage is advocated. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Big Flats, WI
- Average high temperature in September: 70.3°F
The warmest month (with the highest average high temperature) is July (78.8°F).
The month with the lowest average high temperature is January (21.7°F).
- Average low temperature in September: 52°F
The month with the highest average low temperature is July (60.6°F).
The coldest month (with the lowest average low temperature) is January (9.9°F).
Average pressure in September
Big Flats, WI
- Average pressure in September: 30.02"Hg
The months with the highest atmospheric pressure are January and February (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Big Flats, WI
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (10mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
Big Flats, WI
- Average humidity in September: 79%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is April (75%).
Average rainfall in September
Big Flats, WI
- Average rainfall in September: 2.24"
The wettest month (with the highest rainfall) is June (3.5").
The driest month (with the least rainfall) is February (0.98").
Average rainfall days in September
Big Flats, WI
- Average rainfall days in September: 11.4 days
The month with the highest number of rainy days is June (16.6 days).
The month with the least rainy days is January (3.9 days).
Average snowfall in September
Big Flats, WI
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.96").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Big Flats, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Big Flats, WI
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 12min).
Average sunshine days in September
Big Flats, WI
- Average sunshine days in September: 16.7 days
The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is May (12.3 days).
Average UV index in September
Big Flats, WI
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in September
Big Flats, WI
- Average cloud cover in September: 34
The month with the most cloud cover is January (Cloud cover 67).
The months with the least cloud cover are July and August (Cloud cover 33).
Average visibility in September
Big Flats, WI
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and July (5mi).





