September weather forecastCharles City, IA
September
Weather in September
September welcomes a remarkable change in weather in Charles City as the heat of August gives way to the mildness of fall. Temperatures start dipping, alluding to the forthcoming fall season. The precipitation levels continue to stay low at 2.09" (53mm), paving the way for outdoor autumn activities. Reduced daylight hours serve as a rustic backdrop to the transforming cityscape. The unpredictable weather of September signifies an exciting shift in mood, effectively ushering in the fall season.Temperature
During the shift to September, a minor reduction in average high-temperature is observed, shifting from a warm 77.5°F (25.3°C) in August to a pleasant 72.1°F (22.3°C). Throughout September, Charles City records an average temperature of 53.4°F (11.9°C) at night.Humidity
In September, the average relative humidity is 79%.Rainfall
In September, in Charles City, the rain falls for 11.2 days. Throughout September, 2.09" (53mm) of precipitation is accumulated. In Charles City, during the entire year, the rain falls for 136.1 days and collects up to 27.32" (694mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Charles City, the average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:35 am and sunset at 7:44 pm. On the last day of September, sunrise is at 7:07 am and sunset at 6:53 pm CDT.
Sunshine
The average sunshine in September is 8.9h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the maximum UV index of 4 transforms into these recommendations:
Be vigilant - A duty to shield skin and eyes from injury exists. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Charles City, IA
- Average high temperature in September: 72.1°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is January (22.6°F).
- Average low temperature in September: 53.4°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 (10.6°F).
Average pressure in September
Charles City, IA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Charles City, IA
- Average wind speed in September: 8.3mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (7.1mph).
Average humidity in September
Charles City, IA
- Average humidity in September: 79%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Charles City, IA
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is June (4.17").
The driest month (with the least rainfall) is January (1.14").
Average rainfall days in September
Charles City, IA
- Average rainfall days in September: 11.2 days
The month with the highest number of rainy days is May (19.2 days).
The month with the least rainy days is February (4.3 days).
Average snowfall in September
Charles City, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (6.5").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Charles City, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (14.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Charles City, 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: 8h and 54min
The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
Charles City, IA
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is October (17.5 days).
The month with the least sunshine days is June (9.3 days).
Average UV index in September
Charles City, IA
- Average UV index in September: 4
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February and December (UV index 1).
Average cloud cover in September
Charles City, IA
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
Charles City, IA
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, September, October and November (6mi).
The months with the lowest visibility are January, February, July, August and December (5mi).
