September weather forecastAnkeny, IA
September
Weather in September
September brings in the season of fall to Ankeny, Iowa, accompanied by a significant change in weather patterns. Mellow sunshine fills the day, evident in the decreasing daylight hours, leading to milder temperatures. The rainfall remains consistent, replenishing the land before the onset of colder months. A fall in temperature nights, coupled with beautiful autumn foliage, begins to show signs of the impending winter. The transition holds a special charm as the weather gently seizes summer, paving the way for autumn.Temperature
Ankeny's September weather shows a modest shift in high-temperatures, falling from August's 81.1°F (27.3°C) to a still warm 75.2°F (24°C). The average temperature during September nights dips to a moderate 55.9°F (13.3°C).Humidity
The average relative humidity in September is 76%.Rainfall
In Ankeny, in September, during 10.8 rainfall days, 2.6" (66mm) of precipitation is typically accumulated. In Ankeny, during the entire year, the rain falls for 129.8 days and collects up to 25.91" (658mm) of precipitation.Snowfall
In Ankeny, Iowa, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:41 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:11 am and sunset at 6:57 pm CDT.
Sunshine
The average sunshine in September 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 unprotected exposure to Sun's UV rays for average individuals.Note: A typical high UV index of 4 in September suggests the following recommendations:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Ankeny, IA
- Average high temperature in September: 75.2°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (27.7°F).
- Average low temperature in September: 55.9°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (14.4°F).
Average pressure in September
Ankeny, 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 (29.88"Hg).
Average wind speed in September
Ankeny, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in September
Ankeny, IA
- Average humidity in September: 76%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Ankeny, IA
- Average rainfall in September: 2.6"
The wettest month (with the highest rainfall) is May (3.98").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days in September
Ankeny, IA
- Average rainfall days in September: 10.8 days
The month with the highest number of rainy days is June (17.2 days).
The month with the least rainy days is February (3.7 days).
Average snowfall in September
Ankeny, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.17").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Ankeny, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Ankeny, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
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 24min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in September
Ankeny, IA
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is June (11 days).
Average UV index in September
Ankeny, 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, February, October, November and December (UV index 2).
Average cloud cover in September
Ankeny, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are July and September (Cloud cover 29).
Average visibility in September
Ankeny, 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).
