September weather forecast
Waukesha, WI

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Weather in September

September brings the start of the fall season in Waukesha, Wisconsin. A significant drop in temperature is witnessed, signaling the end of the summer heat. Rain becomes less frequent with a decrease to 0.87" (22mm) of rainfall over just 10.3 days. The city basks in a balanced amount of sun and clouds, a trait distinctive to this transitionary month. The wind takes on a refreshing nip, becoming a harbinger of the approaching cold months.

Temperature

Waukesha's weather in September involves a mild decrease in the average high-temperature, moving down slightly from August's warm 76.8°F (24.9°C) to a pleasant 70.7°F (21.5°C). The nights of September anticipate an average low-temperature of 54.7°F (12.6°C).

Humidity

In September, the average relative humidity in Waukesha is 79%.

Rainfall

In September, in Waukesha, the rain falls for 10.3 days. Throughout September, 0.87" (22mm) of precipitation is accumulated. Throughout the year, in Waukesha, there are 114.5 rainfall days, and 12.2" (310mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall.

Daylight

In September, the average length of the day in Waukesha is 12h and 29min.
On the first day of the month, sunrise is at 6:18 am and sunset at 7:27 pm. On the last day of September, in Waukesha, sunrise is at 6:49 am and sunset at 6:35 pm CDT.

Sunshine

The average sunshine in September in Waukesha is 9.1h.

UV index

In Waukesha, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum daily UV index of 4 during September morphs into the following directions:
Guard yourself - Avoiding sunburn is suggested. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
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Frequently asked questions

What is the usual temperature for Waukesha in September?

In Waukesha, in September, the average high-temperature is 70.7°F (21.5°C), and the average low-temperature is 54.7°F (12.6°C).

What is the average humidity in September in Waukesha?

In Waukesha, Wisconsin, the average relative humidity in September is 79%.

How much does it rain in Waukesha in September?

In September, the rain falls for 10.3 days. Throughout September, 0.87" (22mm) of precipitation is accumulated.

When it does not snow in Waukesha?

In Waukesha, Wisconsin, snow does not fall in May through September.

Does it snow in Waukesha in September?

In Waukesha, Wisconsin, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September in Waukesha?

The average day length in September in Waukesha is 12h and 29min.

When is the sunrise / sunset in September in Waukesha?

In September, on the first day of the month, sunrise is at 6:18 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:35 pm CDT.

How long on average sun shines in September in Waukesha?

In September, the average sunshine duration is 9.1h.

What is the UV index reading in September in Waukesha?

The average daily maximum UV index in September in Waukesha, Wisconsin, is 4. A UV Index of 3 to 5 symbolizes a moderate vulnerability from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Waukesha, WI

Average temperature in September - Waukesha, WI
  • Average high temperature in September: 70.7°F

The warmest month (with the highest average high temperature) is July (78.1°F).
The month with the lowest average high temperature is January (25°F).

  • Average low temperature in September: 54.7°F

The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (14°F).

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Average pressure in September
Waukesha, WI

Average pressure in September - Waukesha, WI
  • Average pressure in September: 30.03"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

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Average wind speed in September
Waukesha, WI

Average wind speed in September - Waukesha, WI
  • Average wind speed in September: 7.9mph

The windiest months (with the highest average wind speed) are January and February (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).

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Average humidity in September
Waukesha, WI

Average humidity in September - Waukesha, WI
  • Average humidity in September: 79%

The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are April, October and November (77%).

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Average rainfall in September
Waukesha, WI

Average rainfall in September - Waukesha, WI
  • Average rainfall in September: 0.87"

The wettest month (with the highest rainfall) is July (1.73").
The driest months (with the least rainfall) are February and December (0.51").

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Average rainfall days in September
Waukesha, WI

Average rainfall days in September - Waukesha, WI
  • Average rainfall days in September: 10.3 days

The month with the highest number of rainy days is July (14.3 days).
The month with the least rainy days is February (3.6 days).

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Average snowfall in September
Waukesha, WI

Average snowfall in September - Waukesha, WI
  • Average snowfall in September: 0"

The month with the highest snowfall is January (1.57").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in September
Waukesha, WI

Average snowfall days in September - Waukesha, WI
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (11.2 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
Waukesha, WI

Average daylight in September / Average sunshine in September - Waukesha, WI
  • Average daylight in September: 12h and 3min

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 1min

The months with the most sunshine are July and August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).

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Average sunshine days in September
Waukesha, WI

Average sunshine days in September - Waukesha, WI
  • Average sunshine days in September: 16.9 days

The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is July (13.3 days).

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Average UV index in September
Waukesha, WI

Average UV index in September - Waukesha, WI
  • Average UV index in September: 4

The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

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Average cloud cover in September
Waukesha, WI

Average cloud cover in September - Waukesha, WI
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 29).

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Average visibility in September
Waukesha, WI

Average visibility in September - Waukesha, 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).

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Waukesha, Wisconsin, USA

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