Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The shift into September uncovers an average high-temperature of a still moderately hot 74.1°F (23.4°C), subtly different from the previous month. Nightly temperatures drop to an average low of 54.5°F (12.5°C) in September.Humidity
In September, the average relative humidity is 74%.Rainfall
In September, the rain falls for 11.7 days. Throughout September, 2.4" (61mm) of precipitation is accumulated. In Arnold, during the entire year, the rain falls for 130.6 days and collects up to 25" (635mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Arnold, the average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:42 am and sunset at 7:50 pm. On the last day of September, sunrise is at 7:13 am and sunset at 6:59 pm CDT.
Sunshine
In Arnold, the average sunshine in September is 9.2h.UV index
In Arnold, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the average person.Note: A maximum high UV index of 4 in September translates into the following recommendations:
Adopt protective measures - Suggestions to resist sunburn are offered. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September in Arnold?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Arnold have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Arnold have in September?
How high is the UV index in September?
Average temperature in September
Arnold, IA
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (24.3°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (63.7°F).
The coldest month (with the lowest average low temperature) is January (11.7°F).
Average pressure in September
Arnold, IA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Arnold, IA
- Average wind speed in September: 8.5mph
The windiest month (with the highest average wind speed) is April (10.9mph).
The calmest months (with the lowest average wind speed) are July and August (7.3mph).
Average humidity in September
Arnold, IA
- Average humidity in September: 74%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (68%).
Average rainfall in September
Arnold, IA
- Average rainfall in September: 2.4"
The wettest month (with the highest rainfall) is June (3.7").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days in September
Arnold, IA
- Average rainfall days in September: 11.7 days
The month with the highest number of rainy days is June (17.3 days).
The month with the least rainy days is February (3.7 days).
Average snowfall in September
Arnold, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (5").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Arnold, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Arnold, IA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in September
Arnold, IA
- Average sunshine days in September: 16.4 days
The month with the most sunshine days is November (18.6 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in September
Arnold, 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, November and December (UV index 2).
Average cloud cover in September
Arnold, IA
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are July and September (Cloud cover 30).
Average visibility in September
Arnold, 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).
Arnold, Iowa, USA
Weather forecast for your location
2. Allow the app to use your location