September weather forecastBrookfield, WI
September
Weather in September
September in Brookfield signifies the arrival of autumn with cooling temperatures, shorter days, and an increase in cloud cover. Despite the onset of autumn, the month maintains generous amounts of sunshine, resulting in an overlap of seasons that some may find enchanting. Away from the summer's intense heat, the weather conditions remain pleasantly warm. The transition from lush green landscapes to a warm autumn palette begins, treating observers to a colourful spectacle. Indeed, Brookfield's weather in September serves as a picturesque gateway to the golden autumn season.Temperature
September's arrival aligns with a minor decrease in average high-temperatures, from August's moderately hot 77°F (25°C) to a pleasant 70.2°F (21.2°C). Throughout September, Brookfield witnesses a nighttime temperature average of 56.1°F (13.4°C).Humidity
In Brookfield, the average relative humidity in September is 78%.Rainfall
In Brookfield, in September, it is raining for 11.5 days, with typically 1.54" (39mm) of accumulated precipitation. In Brookfield, during the entire year, the rain falls for 129.9 days and collects up to 19.69" (500mm) of precipitation.Snowfall
In Brookfield, snow does not fall in June through September.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:17 am and sunset at 7:26 pm. On the last day of September, sunrise is at 6:49 am and sunset at 6:34 pm CDT.
Sunshine
In Brookfield, the average sunshine in September is 9.1h.UV index
In Brookfield, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: The maximum UV index of 4 during September leads to these instructions:
Act with care - Obligation to protect against skin and eye damage is highlighted. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Boost your sun resistance with garments that are densely woven yet spacious.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Brookfield, WI
- Average high temperature in September: 70.2°F
The warmest month (with the highest average high temperature) is July (77.9°F).
The month with the lowest average high temperature is January (25.3°F).
- Average low temperature in September: 56.1°F
The month with the highest average low temperature is July (63.7°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).
Average pressure in September
Brookfield, 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
Brookfield, WI
- Average wind speed in September: 8.2mph
The windiest month (with the highest average wind speed) is January (11mph).
The calmest month (with the lowest average wind speed) is July (6.9mph).
Average humidity in September
Brookfield, WI
- Average humidity in September: 78%
The month with the highest relative humidity is January (86%).
The months with the lowest relative humidity are April, October and November (76%).
Average rainfall in September
Brookfield, WI
- Average rainfall in September: 1.54"
The wettest month (with the highest rainfall) is July (2.6").
The driest month (with the least rainfall) is December (0.75").
Average rainfall days in September
Brookfield, WI
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is July (16.3 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in September
Brookfield, WI
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.39").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Brookfield, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Brookfield, 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 6min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
Brookfield, WI
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is December (18.6 days).
The month with the least sunshine days is July (12.1 days).
Average UV index in September
Brookfield, 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
Brookfield, WI
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in September
Brookfield, 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).
