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
With the commencement of September, Viola records a moderate temperature decline, with the average high easing from August's 81°F (27.2°C) to a still warm 75.4°F (24.1°C). The low-temperature in Viola averages to a moderate 56.3°F (13.5°C) during the nights of September.Humidity
In Viola, Illinois, the average relative humidity in September is 76%.Rainfall
In Viola, during September, the rain falls for 9.7 days and regularly aggregates up to 1.46" (37mm) of precipitation. In Viola, during the entire year, the rain falls for 121.3 days and collects up to 17.72" (450mm) of precipitation.Snowfall
In Viola, snow does not fall in May through September.Daylight
In September, the average length of the day in Viola is 12h and 28min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:34 pm. On the last day of September, sunrise is at 6:58 am and sunset at 6:45 pm CDT.
Sunshine
In Viola, the average sunshine in September is 9.5h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum UV index of 4 during September leads to these instructions:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Viola in September?
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?
What time are sunrise and sunset in September in Viola?
How long on average sun shines in September in Viola?
What is the UV index reading in September in Viola?
Average temperature in September
Viola, IL
- Average high temperature in September: 75.4°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (16.9°F).
Average pressure in September
Viola, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Viola, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
Viola, IL
- Average humidity in September: 76%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Viola, IL
- Average rainfall in September: 1.46"
The wettest month (with the highest rainfall) is May (2.76").
The driest month (with the least rainfall) is December (0.67").
Average rainfall days in September
Viola, IL
- Average rainfall days in September: 9.7 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in September
Viola, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.4").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Viola, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.8 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
Viola, IL
- 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 18min).
- Average sunshine in September: 9h and 3min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Viola, IL
- Average sunshine days in September: 19 days
The month with the most sunshine days is January (20.3 days).
The month with the least sunshine days is May (12.1 days).
Average UV index in September
Viola, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Viola, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are August and September (Cloud cover 29).
Average visibility in September
Viola, IL
- 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, Illinois, USA
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