September weather forecastSully, IA
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Sully, Iowa, with an average temperature fluctuating between 55.8°F (13.2°C) and 74.7°F (23.7°C).Temperature
A subtle change in temperatures is noted as August gives way to September, with average highs reducing from 80.6°F (27°C) to a still moderately hot 74.7°F (23.7°C). Sully, in the month of September, anticipates a consistent average low-temperature of 55.8°F (13.2°C).Humidity
In Sully, the average relative humidity in September is 77%.Rainfall
In September, in Sully, the rain falls for 9.6 days. Throughout September, 1.3" (33mm) of precipitation is accumulated. Throughout the year, in Sully, there are 106.7 rainfall days, and 11.77" (299mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall in Sully.Daylight
In Sully, the average length of the day in September is 12h and 28min.On the first day of September in Sully, sunrise is at 6:38 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:54 pm CDT.
Sunshine
In September, the average sunshine in Sully is 9.4h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Heed the precautions - It is counselled to guard against solar damage. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sully, IA
- Average high temperature in September: 74.7°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (27.1°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (14.4°F).
Average pressure in September
Sully, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Sully, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in September
Sully, IA
- Average humidity in September: 77%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Sully, IA
- Average rainfall in September: 1.3"
The wettest month (with the highest rainfall) is May (2.13").
The driest months (with the least rainfall) are January, February and December (0.39").
Average rainfall days in September
Sully, IA
- Average rainfall days in September: 9.6 days
The month with the highest number of rainy days is May (14.7 days).
The month with the least rainy days is February (3.4 days).
Average snowfall in September
Sully, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.73").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Sully, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Sully, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 24min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Sully, IA
- Average sunshine days in September: 18.1 days
The month with the most sunshine days is December (22.9 days).
The month with the least sunshine days is June (12.2 days).
Average UV index in September
Sully, 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
Sully, IA
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are July and September (Cloud cover 30).
Average visibility in September
Sully, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
