Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average sea temperature in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
With September's onset, the weather reveals a slight temperature decrease, transitioning from a moderately hot 77°F (25°C) in August to an agreeable 69.6°F (20.9°C). Green Bay's nighttime temperature during September is consistently averaged at a fresh 52.3°F (11.3°C).Humidity
The average relative humidity in September is 79%.Rainfall
In Green Bay, in September, during 11.6 rainfall days, 1.57" (40mm) of precipitation is typically accumulated. Throughout the year, there are 130.8 rainfall days, and 24.8" (630mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall in Green Bay.Ocean temperature
In Green Bay, in September, the average water temperature is 63.9°F (17.7°C).Note: Swimming in 63.9°F (17.7°C) is not a pleasurable activity for the majority of people. Breathing becomes increasingly challenging as water temperature descends from 69.8°F (21°C) to 59°F (15°C).
Daylight
In Green Bay, the average length of the day in September is 12h and 30min.On the first day of the month, sunrise is at 6:15 am and sunset at 7:28 pm. On the last day of September, sunrise is at 6:49 am and sunset at 6:33 pm CDT.
Sunshine
The average sunshine in September is 8.4h.UV index
The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: A maximum high daily UV index of 3 during September translates into the following directions:
Heed the precautions - Suggestions to avoid sunburn are made. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in Green Bay in September?
What is the ocean temperature in September?
What is the average length of the day in September?
What time are sunrise and sunset in September in Green Bay?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Green Bay, WI
- Average high temperature in September: 69.6°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 (22.6°F).
- Average low temperature in September: 52.3°F
The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (12.4°F).
Average pressure in September
Green Bay, WI
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Green Bay, WI
- Average wind speed in September: 8.1mph
The windiest months (with the highest average wind speed) are January and February (10.1mph).
The calmest months (with the lowest average wind speed) are July and August (7.2mph).
Average humidity in September
Green Bay, WI
- Average humidity in September: 79%
The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are April and May (76%).
Average rainfall in September
Green Bay, WI
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is May (3.31").
The driest month (with the least rainfall) is January (1.18").
Average rainfall days in September
Green Bay, WI
- Average rainfall days in September: 11.6 days
The month with the highest number of rainy days is May (15.9 days).
The month with the least rainy days is February (3.7 days).
Average snowfall in September
Green Bay, WI
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.79").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Green Bay, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (15.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in September
Green Bay, WI
- Average sea temperature in September: 63.8°F
The best month for swimming (with the highest average sea temperature) is August (67.6°F).
The coldest month (with the lowest average sea temperature) is February (36.1°F).
Average daylight in September /
Average sunshine in September
Green Bay, WI
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 3h and 24min).
Average sunshine days in September
Green Bay, WI
- Average sunshine days in September: 17 days
The months with the most sunshine days are September and November (17 days).
The month with the least sunshine days is April (11.6 days).
Average UV index in September
Green Bay, WI
- Average UV index in September: 3
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in September
Green Bay, WI
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 65).
The months with the least cloud cover are July and August (Cloud cover 33).
Average visibility in September
Green Bay, WI
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
Green Bay, Wisconsin, USA
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