September weather forecastAllerton, IA
September
Weather in September
The first month of the autumn, September, is still a warm month in Allerton, Iowa, with an average temperature fluctuating between 56.5°F (13.6°C) and 75.9°F (24.4°C).Temperature
September signifies a gentle decline in Allerton's average high-temperature, easing from 82°F (27.8°C) in August to a still warm 75.9°F (24.4°C). During the nights in September, an average low-temperature of 56.5°F (13.6°C) is observed.Humidity
In Allerton, the average relative humidity in September is 77%.Rainfall
In Allerton, in September, it is raining for 11 days, with typically 2.13" (54mm) of accumulated precipitation. In Allerton, during the entire year, the rain falls for 125.7 days and collects up to 20.39" (518mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Allerton, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:41 am and sunset at 7:45 pm. On the last day of September, sunrise is at 7:09 am and sunset at 6:56 pm CDT.
Sunshine
In Allerton, 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 health risk from exposure to the Sun's UV radiation for average individuals.Note: The maximum UV index of 4 during September translates into these guidelines:
Be vigilant - Suggestions to stave off sun damage are provided. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Allerton, IA
- Average high temperature in September: 75.9°F
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (30°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).
Average pressure in September
Allerton, IA
- Average pressure in September: 30.02"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
Allerton, IA
- Average wind speed in September: 8mph
The windiest months (with the highest average wind speed) are January and March (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in September
Allerton, 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
Allerton, IA
- Average rainfall in September: 2.13"
The wettest month (with the highest rainfall) is June (3.31").
The driest months (with the least rainfall) are January and December (0.71").
Average rainfall days in September
Allerton, IA
- Average rainfall days in September: 11 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is January (4.5 days).
Average snowfall in September
Allerton, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.23").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Allerton, 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
Allerton, 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 18min
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
Allerton, IA
- Average sunshine days in September: 17.2 days
The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is June (10.7 days).
Average UV index in September
Allerton, 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
Allerton, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are July, August and September (Cloud cover 29).
Average visibility in September
Allerton, 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).
