September weather forecastArmstrong, IA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Armstrong, Iowa, with an average temperature varying between 53.8°F (12.1°C) and 72.7°F (22.6°C).Temperature
September brings a slight decrease in the average high-temperature, shifting from a warm 78.1°F (25.6°C) in August to a pleasant 72.7°F (22.6°C). In September, the nighttime temperature lowers to an average of 53.8°F (12.1°C).Humidity
In Armstrong, the average relative humidity in September is 74%.Rainfall
In September, the rain falls for 11.7 days. Throughout September, 2.28" (58mm) of precipitation is accumulated. Throughout the year, there are 123.7 rainfall days, and 23.66" (601mm) of precipitation is accumulated.Snowfall
In Armstrong, snow does not fall in June through September.Daylight
In Armstrong, the average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:42 am and sunset at 7:52 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 7:00 pm CDT.
Sunshine
In Armstrong, the average sunshine in September is 9.1h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: In September, the maximum UV index of 4 translates into these guidelines:
Act with care - The suggestion to avoid sunburn is emphasized. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. 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
Average temperature in September
Armstrong, IA
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (22.5°F).
- Average low temperature in September: 53.8°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (9.9°F).
Average pressure in September
Armstrong, IA
- Average pressure in September: 30"Hg
The months with the highest atmospheric pressure are January and February (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Armstrong, IA
- Average wind speed in September: 8.9mph
The windiest month (with the highest average wind speed) is January (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.6mph).
Average humidity in September
Armstrong, IA
- Average humidity in September: 74%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is October (68%).
Average rainfall in September
Armstrong, IA
- Average rainfall in September: 2.28"
The wettest month (with the highest rainfall) is June (3.7").
The driest month (with the least rainfall) is January (0.87").
Average rainfall days in September
Armstrong, IA
- Average rainfall days in September: 11.7 days
The month with the highest number of rainy days is June (18 days).
The month with the least rainy days is February (2.3 days).
Average snowfall in September
Armstrong, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.8").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Armstrong, 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
Armstrong, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 9h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Armstrong, IA
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is June (10.1 days).
Average UV index in September
Armstrong, 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 February (UV index 1).
Average cloud cover in September
Armstrong, IA
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 59).
The months with the least cloud cover are July and September (Cloud cover 31).
Average visibility in September
Armstrong, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
