September weather forecastBrown Deer, WI
September
Weather in September
September, the first month of the autumn in Brown Deer, is still a pleasant month, with temperature in the range of an average high of 69.4°F (20.8°C) and an average low of 58.1°F (14.5°C).Temperature
With the commencement of September, Brown Deer records a moderate temperature decline, with the average high easing from August's moderately hot 75.6°F (24.2°C) to a pleasant 69.4°F (20.8°C). Brown Deer's average low-temperature in September is measured at a refreshing 58.1°F (14.5°C).Humidity
The average relative humidity in September is 77%.Rainfall
In Brown Deer, during September, the rain falls for 11.2 days and regularly aggregates up to 1.54" (39mm) of precipitation. Throughout the year, there are 129.5 rainfall days, and 18.62" (473mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:16 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:34 pm CDT.
Sunshine
In September, the average sunshine is 9.3h.UV index
In Brown Deer, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum high daily UV index of 4 during September translates into the following directions:
Heed the precautions - It is counselled to guard against solar damage. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Brown Deer, WI
- Average high temperature in September: 69.4°F
The warmest month (with the highest average high temperature) is July (75.7°F).
The month with the lowest average high temperature is January (26.8°F).
- Average low temperature in September: 58.1°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (17.1°F).
Average pressure in September
Brown Deer, WI
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January, February and March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Brown Deer, WI
- Average wind speed in September: 9.3mph
The windiest month (with the highest average wind speed) is January (12.6mph).
The calmest month (with the lowest average wind speed) is July (7.7mph).
Average humidity in September
Brown Deer, WI
- Average humidity in September: 77%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is October (75%).
Average rainfall in September
Brown Deer, WI
- Average rainfall in September: 1.54"
The wettest month (with the highest rainfall) is July (2.56").
The driest month (with the least rainfall) is December (0.71").
Average rainfall days in September
Brown Deer, WI
- Average rainfall days in September: 11.2 days
The months with the highest number of rainy days are May, June and July (15.2 days).
The month with the least rainy days is February (4.5 days).
Average snowfall in September
Brown Deer, WI
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.17").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Brown Deer, 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
Brown Deer, WI
- Average daylight in September: 12h and 30min
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: 9h and 18min
The months with the most sunshine are July and August (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Brown Deer, WI
- Average sunshine days in September: 16.7 days
The month with the most sunshine days is December (18.2 days).
The month with the least sunshine days is June (12.3 days).
Average UV index in September
Brown Deer, WI
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Brown Deer, WI
- Average cloud cover in September: 28
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is July (Cloud cover 26).
Average visibility in September
Brown Deer, WI
- 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).
