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 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
The advent of September reveals an average high-temperature of a pleasant 72.5°F (22.5°C), showing minimal difference from the prior month. The nighttime temperature dips to a fresh 53.4°F (11.9°C) on average during September.Humidity
In Rock Falls, the average relative humidity in September is 78%.Rainfall
In Rock Falls, in September, it is raining for 11.5 days, with typically 2.52" (64mm) of accumulated precipitation. In Rock Falls, during the entire year, the rain falls for 129.5 days and collects up to 25.98" (660mm) of precipitation.Snowfall
June through September are months without snowfall in Rock Falls, Iowa.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:37 am and sunset at 7:46 pm. On the last day of September, in Rock Falls, sunrise is at 7:09 am and sunset at 6:54 pm CDT.
Sunshine
The average sunshine in September in Rock Falls, Iowa, is 8.9h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Rock Falls?
What is the average humidity in September in Rock Falls?
How many days does it rain in September in Rock Falls?
When it does not snow in Rock Falls?
Does it snow in Rock Falls in September?
What is the average length of the day in September in Rock Falls?
When is the sunrise / sunset in September in Rock Falls?
How long on average sun shines in September in Rock Falls?
What is the UV index intensity in September in Rock Falls?
Average temperature in September
Rock Falls, IA
- Average high temperature in September: 72.5°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 (22.5°F).
- Average low temperature in September: 53.4°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (10°F).
Average pressure in September
Rock Falls, IA
- Average pressure in September: 30.01"Hg
The months with the highest atmospheric pressure are January and February (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Rock Falls, IA
- Average wind speed in September: 8.3mph
The windiest months (with the highest average wind speed) are January and April (10.7mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity in September
Rock Falls, IA
- Average humidity in September: 78%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Rock Falls, IA
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is June (3.98").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days in September
Rock Falls, IA
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is June (17.8 days).
The month with the least rainy days is February (3 days).
Average snowfall in September
Rock Falls, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.94").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Rock Falls, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.7 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, IA
- Average daylight in September: 12h and 3min
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 0min).
- Average sunshine in September: 8h and 5min
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 36min).
Average sunshine days in September
Rock Falls, IA
- Average sunshine days in September: 16.6 days
The month with the most sunshine days is November (17.7 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in September
Rock Falls, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Rock Falls, IA
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
Rock Falls, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January and July (5mi).
Rock Falls, Iowa, USA
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