September weather forecastBayfield, WI

September

Weather in September

September marks the gradual arrival of autumn. A drop in temperature from 72.5°F (22.5°C) in August to 65.3°F (18.5°C) signifies the turning of the seasons. The atmosphere starts shimmering in dazzling autumn colors with a decrease in daylight hours. It's a wonderful time to explore outdoor attractions whilst the weather is still agreeably warm. Light layers of clothing are recommended for the chillier evenings.

Temperature

September brings a slight decrease in the average high-temperature, shifting from a pleasant 72.5°F (22.5°C) in August to a refreshing 65.3°F (18.5°C). Bayfield, during the nights of September, experiences an average temperature drop to a fresh 52.5°F (11.4°C).

Humidity

In Bayfield, the average relative humidity in September is 78%.

Rainfall

In Bayfield, in September, during 12.5 rainfall days, 1.77" (45mm) of precipitation is typically accumulated. In Bayfield, Wisconsin, during the entire year, the rain falls for 127.9 days and collects up to 22.56" (573mm) of precipitation.

Snowfall

June through September are months without snowfall.

Ocean temperature

In September, the average ocean temperature in Bayfield, Wisconsin, is 57.2°F (14°C).
Note: Swimming in 57.2°F (14°C) poses a severe threat. Even short exposure to 55.4°F (13°C) is chilling, and going below 50°F (10°C) can cause breathing irregularities and intense cold shock, based on one's stamina.

Daylight

In Bayfield, Wisconsin, the average length of the day in September is 12h and 32min.
On the first day of the month, sunrise is at 6:23 am and sunset at 7:42 pm. On the last day of September, in Bayfield, sunrise is at 7:01 am and sunset at 6:44 pm CDT.

Sunshine

In Bayfield, the average sunshine in September is 8.9h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: In September, an average UV index of 4 transforms into the following instructions:
Adopt protective measures - It is advised to guard against sun damage. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.

Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

In September, the average high-temperature and low-temperature are 65.3°F (18.5°C) and 52.5°F (11.4°C) respectively.

In Bayfield, the average relative humidity in September is 78%.

In September, in Bayfield, Wisconsin, the rain falls for 12.5 days. Throughout September, 1.77" (45mm) of precipitation is accumulated.

June through September are months without snowfall in Bayfield.

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

In Bayfield, Wisconsin, in September, the average water temperature is 57.2°F (14°C). Swimming in 57.2°F (14°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

In September, the average day length in Bayfield is 12h and 32min.

In September, on the first day of the month, sunrise is at 6:23 am and sunset at 7:42 pm. On the last day of the month, in Bayfield, Wisconsin, sunrise is at 7:01 am and sunset at 6:44 pm CDT.

The average sunshine duration in September in Bayfield, Wisconsin, is 8.9h.

In September, the average daily maximum UV index in Bayfield is 4. A UV Index of 3 to 5 symbolizes a medium health risk from unprotected exposure to UV radiation.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

72.5°F

65.3°F

50.7°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

7.8mph

9.1mph

10.7mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

13.5

12.5

Average snowfall

0.55"

Average snowfall days

2.6

Average sea temperature

Average daylight

Average sunshine

Average sunshine days

14.9

15.1

13.5

Average UV index

Average cloud cover

Average visibility

Average temperature in September
Bayfield, WI

Average high temperature in September: 65.3°F

The warmest month (with the highest average high temperature) is August (72.5°F).
The month with the lowest average high temperature is January (20.3°F).

Average low temperature in September: 52.5°F

The month with the highest average low temperature is August (57.9°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).

Average pressure in September
Bayfield, WI

Average pressure in September: 30"Hg

The month with the highest atmospheric pressure is February (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in September
Bayfield, WI

Average wind speed in September: 8.7mph

The windiest months (with the highest average wind speed) are January and December (10.6mph).
The calmest month (with the lowest average wind speed) is July (6.9mph).

Average humidity in September
Bayfield, WI

Average humidity in September: 78%

The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is May (75%).

Average rainfall in September
Bayfield, WI

Average rainfall in September: 1.77"

The wettest months (with the highest rainfall) are May and July (2.56").
The driest months (with the least rainfall) are January and February (1.06").

Average rainfall days in September
Bayfield, WI

Average rainfall days in September: 12.5 days

The month with the highest number of rainy days is June (15.9 days).
The month with the least rainy days is February (3.6 days).

Average snowfall in September
Bayfield, WI

Average snowfall in September: 0"

The month with the highest snowfall is January (6.85").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Bayfield, WI

Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (22.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average sea temperature in September
Bayfield, WI

Average sea temperature in September: 57°F

The best month for swimming (with the highest average sea temperature) is August (61°F).
The coldest months (with the lowest average sea temperature) are February, March and April (36°F).

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

Average daylight in September: 12h and 30min

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

Average sunshine in September: 8h and 54min

The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 2h and 24min).

Average sunshine days in September
Bayfield, WI

Average sunshine days in September: 15.1 days

The month with the most sunshine days is September (15.1 days).
The month with the least sunshine days is December (8.7 days).

Average UV index in September
Bayfield, 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, November and December (UV index 1).

Average cloud cover in September
Bayfield, WI

Average cloud cover in September: 35

The month with the most cloud cover is January (Cloud cover 76).
The month with the least cloud cover is August (Cloud cover 29).

Average visibility in September
Bayfield, WI

Average visibility in September: 6mi

The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).