September weather forecastSullivan, WI
September
Weather in September
September, the first month of the autumn in Sullivan, is also an agreeable month, with an average temperature ranging between max 71.8°F (22.1°C) and min 52.7°F (11.5°C).Temperature
Sullivan experiences a moderate temperature shift at the start of September, with average high-temperatures adjusting a bit from a moderately hot 77.5°F (25.3°C) in August to an agreeable 71.8°F (22.1°C). An average low-temperature of 52.7°F (11.5°C) marks the month of September in Sullivan, Wisconsin.Humidity
In September, the average relative humidity is 81%.Rainfall
In Sullivan, during September, the rain falls for 10.5 days and regularly aggregates up to 1.02" (26mm) of precipitation. In Sullivan, during the entire year, the rain falls for 121.6 days and collects up to 14.06" (357mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:19 am and sunset at 7:28 pm. On the last day of September, in Sullivan, sunrise is at 6:51 am and sunset at 6:36 pm CDT.
Sunshine
In September, the average sunshine in Sullivan is 8.5h.UV index
In September, the average daily maximum UV index in Sullivan is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Heed the precautions - Protecting the skin and eyes from damage is compulsory. Minimize direct exposure to the Sun during midday when its radiation is at its peak. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sullivan, WI
- Average high temperature in September: 71.8°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (24.3°F).
- Average low temperature in September: 52.7°F
The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is January (12.2°F).
Average pressure in September
Sullivan, WI
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and February (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Sullivan, WI
- Average wind speed in September: 7.2mph
The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in September
Sullivan, WI
- Average humidity in September: 81%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is April (76%).
Average rainfall in September
Sullivan, WI
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is July (1.93").
The driest month (with the least rainfall) is December (0.55").
Average rainfall days in September
Sullivan, WI
- Average rainfall days in September: 10.5 days
The months with the highest number of rainy days are May and July (15.7 days).
The month with the least rainy days is January (2.8 days).
Average snowfall in September
Sullivan, WI
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Sullivan, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Sullivan, 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: 8h and 30min
The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in September
Sullivan, WI
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is July (11.6 days).
Average UV index in September
Sullivan, 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
Sullivan, WI
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Sullivan, WI
- Average visibility in September: 5mi
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
