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 beginning of September brings a slight decrease in the average high-temperature, transitioning from 79.3°F (26.3°C) in August to a still moderately hot 73.4°F (23°C). Throughout September, an average low-temperature of 54.7°F (12.6°C) is experienced in Viola, Iowa.Humidity
In September, the average relative humidity is 78%.Rainfall
In September, in Viola, the rain falls for 11.4 days. Throughout September, 2.52" (64mm) of precipitation is accumulated. In Viola, during the entire year, the rain falls for 137.5 days and collects up to 27.68" (703mm) of precipitation.Snowfall
In Viola, snow does not fall in May through September.Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:38 pm. On the last day of September, in Viola, sunrise is at 7:02 am and sunset at 6:48 pm CDT.
Sunshine
In September, the average sunshine is 9.2h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: The UV index of 4 during September leads to these advisories:
Ensure safety - Sun damage prevention is strongly urged. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Viola?
What is the average humidity in September in Viola?
How much does it rain in Viola in September?
When it does not snow in Viola?
Does it snow in Viola in September?
What is the average length of the day in September in Viola?
When are sunrise and sunset in September in Viola?
How many hours of sunshine does Viola have in September?
What is the UV index reading in September in Viola?
Average temperature in September
Viola, IA
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (25.5°F).
- Average low temperature in September: 54.7°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).
Average pressure in September
Viola, 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
Viola, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in September
Viola, IA
- Average humidity in September: 78%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Viola, IA
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is May (4.45").
The driest month (with the least rainfall) is February (1.02").
Average rainfall days in September
Viola, IA
- Average rainfall days in September: 11.4 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in September
Viola, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.16").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Viola, 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
Viola, 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 12min).
- Average sunshine in September: 9h and 1min
The months with the most sunshine are July and August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Viola, IA
- Average sunshine days in September: 17.4 days
The month with the most sunshine days is December (18.2 days).
The month with the least sunshine days is May (10.9 days).
Average UV index in September
Viola, IA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Viola, IA
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Viola, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Viola, Iowa, USA
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