September weather forecastSpencer, IA
September
Weather in September
The month of September brings a visible change to Spencer's weather, with a shift from sweltering heat to cooler climes. The aroma of pumpkin spices and apple pies fills the air, signifying autumn's arrival. The changing colors of leaves from green to shades of orange and red bring a refreshing aesthetic to the city's landscapes. The weather, while remaining pleasant, starts to get colder, signaling the onset of the colder months ahead. September, in essence, stands as a bridge between summer and winter for Spencer.Temperature
A mild drop in Spencer's average high-temperature is observed in September, transitioning from a warm 78.3°F (25.7°C) in August to a pleasant 72.9°F (22.7°C). September nights observe an average temperature dip to a fresh 53.8°F (12.1°C).Humidity
The average relative humidity in September is 74%.Rainfall
In September, the rain falls for 10.5 days. Throughout September, 1.3" (33mm) of precipitation is accumulated. Throughout the year, there are 112.3 rainfall days, and 15.31" (389mm) of precipitation is accumulated.Snowfall
In Spencer, snow does not fall in June through September.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:45 am and sunset at 7:54 pm. On the last day of September, sunrise is at 7:17 am and sunset at 7:02 pm CDT.
Sunshine
In Spencer, Iowa, the average sunshine in September is 9h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: In September, a regular UV index of 4 translates into these guidelines:
Ensure safety - Imperative it is to shield skin and eyes from damage. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Spencer, IA
- Average high temperature in September: 72.9°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 (22.8°F).
- Average low temperature in September: 53.8°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (10.6°F).
Average pressure in September
Spencer, IA
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Spencer, IA
- Average wind speed in September: 9mph
The windiest months (with the highest average wind speed) are January and April (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.6mph).
Average humidity in September
Spencer, IA
- Average humidity in September: 74%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (68%).
Average rainfall in September
Spencer, IA
- Average rainfall in September: 1.3"
The wettest month (with the highest rainfall) is June (2.44").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days in September
Spencer, IA
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is May (15.5 days).
The month with the least rainy days is February (2.7 days).
Average snowfall in September
Spencer, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.72").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Spencer, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Spencer, IA
- Average daylight in September: 12h and 30min
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 0min
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 0min).
Average sunshine days in September
Spencer, IA
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is November (20.1 days).
The month with the least sunshine days is June (10.8 days).
Average UV index in September
Spencer, 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
Spencer, IA
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Spencer, 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).
