September weather forecastShell Rock, IA
September
Weather in September
The first month of the autumn, September, is also an agreeable month in Shell Rock, Iowa, with an average temperature fluctuating between 54°F (12.2°C) and 72.9°F (22.7°C).Temperature
The average high-temperature shows a slight dip in September, from August's warm 78.3°F (25.7°C) to a pleasant 72.9°F (22.7°C). In Shell Rock, the average low-temperature during the month of September is a fresh 54°F (12.2°C).Humidity
In September, the average relative humidity in Shell Rock, Iowa, is 78%.Rainfall
In Shell Rock, in September, during 12.8 rainfall days, 2.4" (61mm) of precipitation is typically accumulated. In Shell Rock, during the entire year, the rain falls for 138.7 days and collects up to 28.78" (731mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Shell Rock, the average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:35 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:52 pm CDT.
Sunshine
The average sunshine in September is 9.1h.UV index
In Shell Rock, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: In September, the maximum UV index of 4 transforms into these recommendations:
Undertake precautions - Guarding against sun damage is counselled. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Shell Rock, IA
- Average high temperature in September: 72.9°F
The warmest month (with the highest average high temperature) is July (79.5°F).
The month with the lowest average high temperature is January (23.9°F).
- Average low temperature in September: 54°F
The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (11.3°F).
Average pressure in September
Shell Rock, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Shell Rock, IA
- Average wind speed in September: 8.2mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (7mph).
Average humidity in September
Shell Rock, IA
- Average humidity in September: 78%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Shell Rock, IA
- Average rainfall in September: 2.4"
The wettest month (with the highest rainfall) is June (4.29").
The driest month (with the least rainfall) is January (1.02").
Average rainfall days in September
Shell Rock, IA
- Average rainfall days in September: 12.8 days
The month with the highest number of rainy days is June (19.4 days).
The month with the least rainy days is February (3.9 days).
Average snowfall in September
Shell Rock, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.08").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Shell Rock, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Shell Rock, IA
- 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: 9h and 6min
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 48min).
Average sunshine days in September
Shell Rock, IA
- Average sunshine days in September: 15.5 days
The months with the most sunshine days are October and November (17.8 days).
The month with the least sunshine days is June (9.2 days).
Average UV index in September
Shell Rock, IA
- Average UV index in September: 4
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Shell Rock, IA
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in September
Shell Rock, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
