September weather forecast
Island Lake, WI

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Weather in September

September, the first month of the autumn in Island Lake, is still a pleasant month, with an average temperature varying between 68.9°F (20.5°C) and 49.5°F (9.7°C).

Temperature

September signals a slight drop in average high-temperature, sliding from August's moderately hot 76.6°F (24.8°C) to a pleasant 68.9°F (20.5°C). September brings with it a nighttime average temperature of 49.5°F (9.7°C).

Humidity

In Island Lake, Wisconsin, the average relative humidity in September is 80%.

Rainfall

In Island Lake, in September, it is raining for 13.2 days, with typically 1.85" (47mm) of accumulated precipitation. In Island Lake, during the entire year, the rain falls for 137.4 days and collects up to 26.26" (667mm) of precipitation.

Snowfall

June through September are months without snowfall.

Daylight

In September, the average length of the day is 12h and 31min.
On the first day of the month, sunrise is at 6:28 am and sunset at 7:42 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:47 pm CDT.

Sunshine

The average sunshine in September is 8.4h.

UV index

In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.
Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Undertake precautions - Obligation exists to protect against skin and eye damage. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Updated: Aug 27, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature?

The average high-temperature, in September, in Island Lake, is 68.9°F (20.5°C), while the average low-temperature is 49.5°F (9.7°C).

What is the average humidity in September?

In Island Lake, the average relative humidity in September is 80%.

How many days does it rain in September?

In Island Lake, during September, the rain falls for 13.2 days and regularly aggregates up to 1.85" (47mm) of precipitation.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

In Island Lake, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Island Lake have in September?

In September, the average day length is 12h and 31min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:28 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:47 pm CDT.

How long on average sun shines in September in Island Lake?

In September, the average sunshine duration is 8.4h.

How high is the UV index in September?

The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium hazard to health from exposure to the Sun's UV radiation.
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
Island Lake, WI

Average temperature in September - Island Lake, WI
  • Average high temperature in September: 68.9°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 (18.7°F).

  • Average low temperature in September: 49.5°F

The month with the highest average low temperature is July (58.6°F).
The coldest month (with the lowest average low temperature) is January (6.1°F).

Average pressure in September
Island Lake, WI

Average pressure in September - Island Lake, WI
  • Average pressure in September: 30.01"Hg

The months with the highest atmospheric pressure are January and February (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in September
Island Lake, WI

Average wind speed in September - Island Lake, WI
  • Average wind speed in September: 7.5mph

The windiest month (with the highest average wind speed) is April (8.9mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).

Average humidity in September
Island Lake, WI

Average humidity in September - Island Lake, WI
  • Average humidity in September: 80%

The months with the highest relative humidity are January and February (92%).
The month with the lowest relative humidity is May (76%).

Average rainfall in September
Island Lake, WI

Average rainfall in September - Island Lake, WI
  • Average rainfall in September: 1.85"

The wettest month (with the highest rainfall) is June (4.06").
The driest month (with the least rainfall) is January (0.94").

Average rainfall days in September
Island Lake, WI

Average rainfall days in September - Island Lake, WI
  • Average rainfall days in September: 13.2 days

The month with the highest number of rainy days is May (18.3 days).
The months with the least rainy days are January and February (3.7 days).

Average snowfall in September
Island Lake, WI

Average snowfall in September - Island Lake, WI
  • Average snowfall in September: 0"

The month with the highest snowfall is February (7.44").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Island Lake, WI

Average snowfall days in September - Island Lake, WI
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (17.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Island Lake, WI

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

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in September: 8h and 2min

The month with the most sunshine is July (Average sunshine: 9h and 42min).
The months with the least sunshine are January and February (Average sunshine: 2h and 48min).

Average sunshine days in September
Island Lake, WI

Average sunshine days in September - Island Lake, WI
  • Average sunshine days in September: 14.1 days

The month with the most sunshine days is October (15.6 days).
The month with the least sunshine days is June (9.3 days).

Average UV index in September
Island Lake, WI

Average UV index in September - Island Lake, WI
  • Average UV index in September: 4

The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).

Average cloud cover in September
Island Lake, WI

Average cloud cover in September - Island Lake, WI
  • Average cloud cover in September: 38

The months with the most cloud cover are January and February (Cloud cover 72).
The months with the least cloud cover are July and August (Cloud cover 36).

Average visibility in September
Island Lake, WI

Average visibility in September - Island Lake, WI
  • Average visibility in September: 5mi

The months with the highest visibility are April, May, June, October and November (6mi).
The months with the lowest visibility are January and February (4mi).

Island Lake, Wisconsin, USA

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