September weather forecastAtalissa, IA
September
Weather in September
The first month of the autumn, September, is still a warm month in Atalissa, Iowa, with an average temperature ranging between min 56.1°F (13.4°C) and max 75.2°F (24°C).Temperature
September brings a slight decrease in temperature, down from 80.6°F (27°C) in August to a still warm 75.2°F (24°C). During the nights in September, the temperature averages to a mild 56.1°F (13.4°C).Humidity
In September, the average relative humidity is 76%.Rainfall
In Atalissa, during September, the rain falls for 8.1 days and regularly aggregates up to 0.71" (18mm) of precipitation. In Atalissa, during the entire year, the rain falls for 92.5 days and collects up to 7.68" (195mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:31 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:47 pm CDT.
Sunshine
In Atalissa, the average sunshine in September is 9.3h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: The UV index of 4 during September translates into the following guidance:
Exercise care. People with light skin might get burns in fewer than 30 minutes. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Atalissa, IA
- Average high temperature in September: 75.2°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 (27.5°F).
- Average low temperature in September: 56.1°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (15.4°F).
Average pressure in September
Atalissa, 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 (29.9"Hg).
Average wind speed in September
Atalissa, IA
- Average wind speed in September: 7.9mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
Atalissa, IA
- Average humidity in September: 76%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Atalissa, IA
- Average rainfall in September: 0.71"
The wettest month (with the highest rainfall) is May (1.34").
The driest month (with the least rainfall) is February (0.28").
Average rainfall days in September
Atalissa, IA
- Average rainfall days in September: 8.1 days
The month with the highest number of rainy days is June (13.2 days).
The month with the least rainy days is January (2.8 days).
Average snowfall in September
Atalissa, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.1").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Atalissa, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.4 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Atalissa, 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 18min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Atalissa, IA
- Average sunshine days in September: 20.8 days
The month with the most sunshine days is December (24.4 days).
The month with the least sunshine days is June (14.8 days).
Average UV index in September
Atalissa, 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
Atalissa, IA
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Atalissa, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).





