September weather forecastRock Falls, WI
September
Weather in September
September, the first month of the autumn in Rock Falls, is also an agreeable month, with an average temperature varying between 70.5°F (21.4°C) and 50.9°F (10.5°C).Temperature
Rock Falls's progression into September involves a minor drop in the average high-temperature, slightly receding from a warm 76.8°F (24.9°C) in August to a pleasant 70.5°F (21.4°C). During the month of September, the temperature generally drops to a low average of 50.9°F (10.5°C).Humidity
In September, the average relative humidity is 80%.Rainfall
In September, the rain falls for 12.1 days. Throughout September, 2.28" (58mm) of precipitation is accumulated. Throughout the year, there are 135.6 rainfall days, and 26.57" (675mm) of precipitation is accumulated.Snowfall
In Rock Falls, snow does not fall in June through September.Daylight
In September, the average length of the day is 12h and 31min.On the first day of September, sunrise is at 6:30 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:48 pm CDT.
Sunshine
In Rock Falls, Wisconsin, the average sunshine in September is 8.5h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: A maximum high UV index of 4 in September translates into the following recommendations:
Be vigilant - A duty to shield skin and eyes from injury exists. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rock Falls, WI
- Average high temperature in September: 70.5°F
The warmest month (with the highest average high temperature) is July (78.4°F).
The month with the lowest average high temperature is January (19.9°F).
- Average low temperature in September: 50.9°F
The month with the highest average low temperature is July (60.6°F).
The coldest month (with the lowest average low temperature) is January (6.3°F).
Average pressure in September
Rock Falls, WI
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Rock Falls, WI
- Average wind speed in September: 7.3mph
The windiest month (with the highest average wind speed) is April (9.3mph).
The calmest month (with the lowest average wind speed) is July (6.4mph).
Average humidity in September
Rock Falls, WI
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (91%).
The months with the lowest relative humidity are April and October (77%).
Average rainfall in September
Rock Falls, WI
- Average rainfall in September: 2.28"
The wettest month (with the highest rainfall) is June (4.57").
The driest month (with the least rainfall) is January (0.87").
Average rainfall days in September
Rock Falls, WI
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is June (17.9 days).
The month with the least rainy days is February (3.6 days).
Average snowfall in September
Rock Falls, WI
- Average snowfall in September: 0"
The month with the highest snowfall is February (6.38").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Rock Falls, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (16.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Rock Falls, WI
- Average daylight in September: 12h and 30min
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 30min
The months with the most sunshine are July and August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).
Average sunshine days in September
Rock Falls, WI
- Average sunshine days in September: 15.8 days
The month with the most sunshine days is October (16.3 days).
The month with the least sunshine days is June (9.8 days).
Average UV index in September
Rock Falls, 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, February, November and December (UV index 1).
Average cloud cover in September
Rock Falls, WI
- Average cloud cover in September: 37
The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
Rock Falls, WI
- Average visibility in September: 5mi
The months with the highest visibility are April, May, June, August, October and November (6mi).
The month with the lowest visibility is January (4mi).





