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
September is characterized by a slight reduction in average high-temperature, easing from a tropical 86.5°F (30.3°C) in August to a warm 81.1°F (27.3°C). In Vienna, an average low-temperature of 60.6°F (15.9°C) is recorded during September nights.Heat index
The average heat index in September is calculated to be a tropical 86°F (30°C). If exposure and activity persist, fatigue could ensue, possibly leading to heat cramps.Heat index values are typically calculated for conditions of shade and a light breeze. Exposure to the direct sun might augment heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a numerical representation of warmth when taking temperature and moisture levels into account. The impact of weather on an individual can be subjective, affected by the person's activity and heat perception, which can vary due to elements including wind, clothing, and metabolic differences. With direct sunlight, be aware that it might enhance the heat sensation, raising the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Young children are more at risk than adults since they tend to sweat less. Moreover, their large skin surface in proportion to their small bodies and the high heat production due to their activities contribute to their vulnerability.
Humidity
In Vienna, Illinois, the average relative humidity in September is 73%.Rainfall
The month with the least rainfall is September, when the rain falls for 8.3 days and typically collects 0.47" (12mm) of precipitation.Snowfall
In Vienna, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 25min.On the first day of September in Vienna, sunrise is at 6:26 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:39 pm CDT.
Sunshine
In Vienna, the average sunshine in September is 9.4h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the average person.Note: A daily maximum UV index of 5 in September translates into the following instructions:
Guard yourself - An obligation to protect skin and eyes from harm exists. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Frequently asked questions
What is the temperature in September in Vienna?
What is the average humidity in September in Vienna?
What is the driest month in Vienna?
How many days does it rain in September in Vienna?
When it does not snow in Vienna?
What is the average length of the day in September in Vienna?
When are sunrise and sunset in September in Vienna?
How many hours of sunshine does Vienna have in September?
What is the UV index reading in September in Vienna?
Average temperature in September
Vienna, IL
- Average high temperature in September: 81.1°F
The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is January (40.1°F).
- Average low temperature in September: 60.6°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (27°F).
Average pressure in September
Vienna, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Vienna, IL
- Average wind speed in September: 6.3mph
The windiest months (with the highest average wind speed) are January and February (9mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).
Average humidity in September
Vienna, IL
- Average humidity in September: 73%
The months with the highest relative humidity are March and May (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Vienna, IL
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is June (1.5").
The driest month (with the least rainfall) is September (0.47").
Average rainfall days in September
Vienna, IL
- Average rainfall days in September: 8.3 days
The month with the highest number of rainy days is July (13.1 days).
The months with the least rainy days are January, February and December (7.3 days).
Average snowfall in September
Vienna, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.67").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Vienna, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (3.3 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
Vienna, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 9h and 2min
The months with the most sunshine are June and July (Average sunshine: 10h and 24min).
The months with the least sunshine are January and February (Average sunshine: 4h and 36min).
Average sunshine days in September
Vienna, IL
- Average sunshine days in September: 19.1 days
The month with the most sunshine days is October (21.5 days).
The month with the least sunshine days is June (14.8 days).
Average UV index in September
Vienna, IL
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in September
Vienna, IL
- Average cloud cover in September: 28
The months with the most cloud cover are January and February (Cloud cover 51).
The month with the least cloud cover is September (Cloud cover 28).
Average visibility in September
Vienna, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Vienna, Illinois, USA
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