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 minor change in the average high-temperature, shifting from a hot 86.5°F (30.3°C) in August to a warm 81°F (27.2°C). Anna experiences an average nighttime temperature of 60.6°F (15.9°C) in the month of September.Heat index
The heat index for September is computed to be 84.2°F (29°C). With extended exposure and activity, one might feel exhausted and experience heat cramps.Note that heat index values are valued for light wind and location in the shade. When exposed to the direct sun, the heat index may augment by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', is a fusion of air temperature and moisture levels to demonstrate the sensation of heat. The influence of weather is personal, differing among a variety of individuals based on differences in body mass, stature, and the level of physical activity. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.
Humidity
The average relative humidity in September is 73%.Rainfall
The month with the least rainfall is September, when the rain falls for 10.8 days and typically collects 1.3" (33mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:25 pm. On the last day of September, sunrise is at 6:52 am and sunset at 6:41 pm CDT.
Sunshine
In Anna, the average sunshine in September is 9.5h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 5 in September translates into these instructions:
Guard yourself - Avoiding sunburn is suggested. The Sun's radiation is especially intense around midday; try to stay in shade during this period. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September in Anna?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Anna, IL
- Average high temperature in September: 81°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is January (39.7°F).
- Average low temperature in September: 60.6°F
The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is January (26.8°F).
Average pressure in September
Anna, IL
- 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 (29.94"Hg).
Average wind speed in September
Anna, IL
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is January (9mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).
Average humidity in September
Anna, IL
- Average humidity in September: 73%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Anna, IL
- Average rainfall in September: 1.3"
The wettest month (with the highest rainfall) is April (3.31").
The driest month (with the least rainfall) is September (1.3").
Average rainfall days in September
Anna, IL
- Average rainfall days in September: 10.8 days
The month with the highest number of rainy days is July (15.9 days).
The month with the least rainy days is January (8.4 days).
Average snowfall in September
Anna, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.89").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Anna, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.6 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
Anna, 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 3min
The month with the most sunshine is 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
Anna, IL
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is October (21 days).
The month with the least sunshine days is July (12.8 days).
Average UV index in September
Anna, 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
Anna, IL
- Average cloud cover in September: 28
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is September (Cloud cover 28).
Average visibility in September
Anna, 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).
Anna, Illinois, USA
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