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 arrival of September correlates with a minor temperature reduction, down from August's 81.3°F (27.4°C) to a still moderately hot 75.7°F (24.3°C). In the month of September, the average low-temperature usually rests at a mild 56.1°F (13.4°C).Humidity
In September, the average relative humidity is 76%.Rainfall
In Swan, in September, during 9.5 rainfall days, 1.42" (36mm) of precipitation is typically accumulated. In Swan, during the entire year, the rain falls for 109.9 days and collects up to 12.72" (323mm) of precipitation.Snowfall
In Swan, snow does not fall in May through September.Daylight
In Swan, the average length of the day in September is 12h and 28min.On the first day of September in Swan, sunrise is at 6:40 am and sunset at 7:45 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:56 pm CDT.
Sunshine
The average sunshine in September is 9.4h.UV index
In September, the average daily maximum UV index in Swan is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Heed the precautions - Suggestions to avoid sunburn are made. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Frequently asked questions
What is the temperature in September in Swan?
What is the average humidity in September in Swan?
How many days does it rain in September in Swan?
When it does not snow in Swan?
Does it snow in Swan in September?
What is the average length of the day in September in Swan?
When are sunrise and sunset in September in Swan?
How long on average sun shines in September in Swan?
What is the UV index reading in September in Swan?
Average temperature in September
Swan, IA
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (28.4°F).
- Average low temperature in September: 56.1°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (15.1°F).
Average pressure in September
Swan, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Swan, IA
- Average wind speed in September: 7.9mph
The windiest months (with the highest average wind speed) are January and April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.8mph).
Average humidity in September
Swan, IA
- Average humidity in September: 76%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Swan, IA
- Average rainfall in September: 1.42"
The wettest month (with the highest rainfall) is May (2.28").
The driest months (with the least rainfall) are January and December (0.39").
Average rainfall days in September
Swan, IA
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is February (3.3 days).
Average snowfall in September
Swan, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.97").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Swan, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Swan, IA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Swan, IA
- Average sunshine days in September: 17.9 days
The month with the most sunshine days is December (22.7 days).
The month with the least sunshine days is June (10.9 days).
Average UV index in September
Swan, IA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Swan, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are July, August and September (Cloud cover 29).
Average visibility in September
Swan, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Swan, Iowa, USA
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