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's presence records an average high-temperature of a still warm 77.7°F (25.4°C), closely mirroring August's climate. In the month of September, South Jacksonville experiences an average low-temperature of 58.6°F (14.8°C).Humidity
The average relative humidity in September is 74%.Rainfall
In South Jacksonville, Illinois, in September, during 11.7 rainfall days, 2.64" (67mm) of precipitation is typically accumulated. Throughout the year, there are 148.2 rainfall days, and 29.37" (746mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
In South Jacksonville, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:29 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:44 pm CDT.
Sunshine
The average sunshine in September is 9.4h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: In September, the maximum UV index of 5 suggests these recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
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?
How many days 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?
When are sunrise and sunset in September?
How many hours of sunshine does South Jacksonville have in September?
What is the UV index intensity in September?
Average temperature in September
South Jacksonville, IL
- Average high temperature in September: 77.7°F
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in September: 58.6°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (21°F).
Average pressure in September
South Jacksonville, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
South Jacksonville, IL
- Average wind speed in September: 7mph
The windiest month (with the highest average wind speed) is January (10.1mph).
The calmest month (with the lowest average wind speed) is July (6.1mph).
Average humidity in September
South Jacksonville, IL
- Average humidity in September: 74%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
South Jacksonville, IL
- Average rainfall in September: 2.64"
The wettest month (with the highest rainfall) is June (3.58").
The driest month (with the least rainfall) is December (1.54").
Average rainfall days in September
South Jacksonville, IL
- Average rainfall days in September: 11.7 days
The month with the highest number of rainy days is May (18 days).
The months with the least rainy days are January and February (7.1 days).
Average snowfall in September
South Jacksonville, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.58").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
South Jacksonville, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.6 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
South Jacksonville, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in September
South Jacksonville, IL
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is December (18.5 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in September
South Jacksonville, IL
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
South Jacksonville, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).
Average visibility in September
South Jacksonville, IL
- 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).
South Jacksonville, Illinois, USA
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