September weather forecastRio, WI
September
Weather in September
September, the first month of the autumn in Rio, is still a pleasant month, with an average temperature fluctuating between 51.3°F (10.7°C) and 71.1°F (21.7°C).Temperature
In Rio, the average high-temperature in September slightly decreases from a warm 77.4°F (25.2°C) in August to a pleasant 71.1°F (21.7°C). Throughout September, Rio anticipates an average low-temperature of 51.3°F (10.7°C).Humidity
In September, the average relative humidity is 80%.Rainfall
In Rio, during September, the rain falls for 12.1 days and regularly aggregates up to 2.6" (66mm) of precipitation. Throughout the year, there are 134.5 rainfall days, and 26.97" (685mm) of precipitation is accumulated.Snowfall
In Rio, snow does not fall in June through September.Daylight
In September, the average length of the day is 12h and 29min.On the first day of September in Rio, sunrise is at 6:21 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:39 pm CDT.
Sunshine
In Rio, the average sunshine in September is 8.7h.UV index
The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 3 during September translates into the following guidance:
Put precautions into practice - Ensuring skin and eye safety is a necessity. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rio, WI
- Average high temperature in September: 71.1°F
The warmest month (with the highest average high temperature) is July (78.6°F).
The month with the lowest average high temperature is January (22.6°F).
- Average low temperature in September: 51.3°F
The month with the highest average low temperature is July (61.2°F).
The coldest month (with the lowest average low temperature) is January (10.6°F).
Average pressure in September
Rio, WI
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and February (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Rio, WI
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in September
Rio, WI
- Average humidity in September: 80%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is April (76%).
Average rainfall in September
Rio, WI
- Average rainfall in September: 2.6"
The wettest month (with the highest rainfall) is June (3.54").
The driest month (with the least rainfall) is February (1.1").
Average rainfall days in September
Rio, WI
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is June (17.2 days).
The month with the least rainy days is February (4.2 days).
Average snowfall in September
Rio, WI
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.16").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Rio, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (14.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Rio, WI
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 12min).
Average sunshine days in September
Rio, WI
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is September (16.5 days).
The month with the least sunshine days is June (10.8 days).
Average UV index in September
Rio, WI
- Average UV index in September: 3
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
Rio, WI
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 66).
The months with the least cloud cover are July and August (Cloud cover 34).
Average visibility in September
Rio, WI
- Average visibility in September: 5mi
The months with the highest visibility are March, April, May, June, October and November (6mi).
The months with the lowest visibility are January, February, July, August, September and December (5mi).





