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 transition into September is accompanied by a slight temperature decrease, with the average high-temperature shifting from a warm 78.3°F (25.7°C) in August to a pleasant 72.3°F (22.4°C). In the month of September, Delaware records a consistent average low-temperature of 53.2°F (11.8°C).Humidity
In Delaware, Iowa, the average relative humidity in September is 79%.Rainfall
In September, the rain falls for 8.9 days. Throughout September, 1.3" (33mm) of precipitation is accumulated. In Delaware, during the entire year, the rain falls for 111.7 days and collects up to 13.31" (338mm) of precipitation.Snowfall
May through September are months without snowfall in Delaware.Daylight
In Delaware, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:39 pm. On the last day of September, sunrise is at 7:02 am and sunset at 6:47 pm CDT.
Sunshine
In Delaware, the average sunshine in September is 8.9h.UV index
In September, the average daily maximum UV index in Delaware, Iowa, is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: The UV index of 4 during September translates into the following guidance:
Act with care - The suggestion to avoid sunburn is emphasized. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Frequently asked questions
What is the average September temperature in Delaware?
What is the average humidity in September in Delaware?
How many days does it rain in September in Delaware?
When it does not snow in Delaware?
Does it snow in Delaware in September?
What is the average length of the day in September in Delaware?
What time are sunrise and sunset in September in Delaware?
How many hours of sunshine does Delaware have in September?
What is the UV index reading in September in Delaware?
Average temperature in September
Delaware, IA
- Average high temperature in September: 72.3°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (24.3°F).
- Average low temperature in September: 53.2°F
The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (11.7°F).
Average pressure in September
Delaware, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Delaware, IA
- Average wind speed in September: 8.2mph
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 (7.1mph).
Average humidity in September
Delaware, IA
- Average humidity in September: 79%
The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are April and October (75%).
Average rainfall in September
Delaware, IA
- Average rainfall in September: 1.3"
The wettest month (with the highest rainfall) is May (2.13").
The driest month (with the least rainfall) is December (0.47").
Average rainfall days in September
Delaware, IA
- Average rainfall days in September: 8.9 days
The month with the highest number of rainy days is June (15.4 days).
The month with the least rainy days is February (2.6 days).
Average snowfall in September
Delaware, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Delaware, 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 May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Delaware, IA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 8h and 5min
The months with the most sunshine are July and August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
Delaware, IA
- Average sunshine days in September: 18.5 days
The month with the most sunshine days is December (19.7 days).
The month with the least sunshine days is June (11.7 days).
Average UV index in September
Delaware, IA
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
Delaware, IA
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 63).
The months with the least cloud cover are August and September (Cloud cover 33).
Average visibility in September
Delaware, 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).
Delaware, Iowa, USA
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