September weather forecastDecatur City, IA
September
Weather in September
September, the first month of the autumn in Decatur City, is also a moderately hot month, with temperature in the range of an average low of 56.3°F (13.5°C) and an average high of 76.1°F (24.5°C).Temperature
September marks a gentle change in average high-temperature, declining from August's 81.9°F (27.7°C) to a still moderately hot 76.1°F (24.5°C). During the month of September, the temperature generally drops to a low average of 56.3°F (13.5°C).Humidity
In Decatur City, the average relative humidity in September is 77%.Rainfall
In September, the rain falls for 11.5 days. Throughout September, 2.24" (57mm) of precipitation is accumulated. Throughout the year, there are 132.4 rainfall days, and 20.24" (514mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Decatur City, the average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:43 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 6:58 pm CDT.
Sunshine
The average sunshine in September is 9.4h.UV index
The average daily maximum UV index in September in Decatur City is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 4 during September translates into the following directions:
Act with care - The need to guard against sun damage is communicated. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Decatur City, IA
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (16.9°F).
Average pressure in September
Decatur City, IA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Decatur City, IA
- Average wind speed in September: 7.9mph
The windiest months (with the highest average wind speed) are January, February and March (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.9mph).
Average humidity in September
Decatur City, IA
- Average humidity in September: 77%
The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Decatur City, IA
- Average rainfall in September: 2.24"
The wettest month (with the highest rainfall) is June (3.43").
The driest months (with the least rainfall) are January and December (0.67").
Average rainfall days in September
Decatur City, IA
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is June (17.3 days).
The month with the least rainy days is January (4.8 days).
Average snowfall in September
Decatur City, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.72").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Decatur City, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Decatur City, IA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 24min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in September
Decatur City, IA
- Average sunshine days in September: 16 days
The month with the most sunshine days is December (20.3 days).
The month with the least sunshine days is June (8.9 days).
Average UV index in September
Decatur City, IA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Decatur City, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 51).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in September
Decatur City, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
