September weather forecastWhitefish Bay, WI
September
Weather in September
September, the first month of the autumn in Whitefish Bay, is also an agreeable month, with an average temperature ranging between min 58.1°F (14.5°C) and max 69.4°F (20.8°C).Temperature
A moderate decline in average high-temperatures is noted in September, moving from a moderately hot 75.6°F (24.2°C) in August to a pleasant 69.4°F (20.8°C). Whitefish Bay observes an average low-temperature of 58.1°F (14.5°C) during September.Humidity
In Whitefish Bay, the average relative humidity in September is 77%.Rainfall
In September, the rain falls for 11.2 days. Throughout September, 1.54" (39mm) of precipitation is accumulated. 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.Ocean temperature
In Whitefish Bay, in September, the average water temperature is 66.9°F (19.4°C).Note: For most, swimming in 66.9°F (19.4°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).
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 7:25 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:34 pm CDT.
Sunshine
The average sunshine in September is 9.3h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for average individuals.Note: In September, a regular UV index of 4 translates into these guidelines:
Exercise care. People with light skin might get burns in fewer than 30 minutes. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Whitefish Bay, 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
Whitefish Bay, 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
Whitefish Bay, 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
Whitefish Bay, 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
Whitefish Bay, 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
Whitefish Bay, 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
Whitefish Bay, 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
Whitefish Bay, 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 sea temperature in September
Whitefish Bay, WI
- Average sea temperature in September: 66.9°F
The best month for swimming (with the highest average sea temperature) is August (71.9°F).
The coldest month (with the lowest average sea temperature) is February (36°F).
Average daylight in September /
Average sunshine in September
Whitefish Bay, 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
Whitefish Bay, 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
Whitefish Bay, 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
Whitefish Bay, 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
Whitefish Bay, 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).





