September weather forecastAlleman, IA
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Alleman, Iowa, with an average temperature varying between 55.9°F (13.3°C) and 74.8°F (23.8°C).Temperature
In Alleman, the average high-temperature in September gently drops from a moderately hot 80.2°F (26.8°C) in August to a still warm 74.8°F (23.8°C). An average nighttime temperature of 55.9°F (13.3°C) is observed in Alleman during September.Humidity
The average relative humidity in September is 76%.Rainfall
In September, the rain falls for 11.9 days. Throughout September, 3.11" (79mm) of precipitation is accumulated. In Alleman, during the entire year, the rain falls for 141.4 days and collects up to 29.65" (753mm) of precipitation.Snowfall
In Alleman, 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 9.3h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: A daily high UV index of 4 in September leads to these guidelines:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Alleman, IA
- Average high temperature in September: 74.8°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (26.6°F).
- Average low temperature in September: 55.9°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 (13.6°F).
Average pressure in September
Alleman, 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
Alleman, IA
- Average wind speed in September: 8.1mph
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
Alleman, IA
- Average humidity in September: 76%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Alleman, IA
- Average rainfall in September: 3.11"
The wettest month (with the highest rainfall) is May (4.65").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days in September
Alleman, IA
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is June (19.3 days).
The month with the least rainy days is February (4.3 days).
Average snowfall in September
Alleman, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.57").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Alleman, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Alleman, 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 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
Alleman, IA
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is June (8.4 days).
Average UV index in September
Alleman, 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
Alleman, IA
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in September
Alleman, 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).
