September weather forecastClay City, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Clay City, Illinois, with an average temperature ranging between min 59.9°F (15.5°C) and max 78.6°F (25.9°C).Temperature
With the onset of September, the average high-temperature registers at a still warm 78.6°F (25.9°C), subtly different from August's 82.9°F (28.3°C). An average low-temperature of 59.9°F (15.5°C) is noted during the month of September.Humidity
In September, the average relative humidity is 74%.Rainfall
The months with the least rainfall are February and September Rain falls for 13.3 days and accumulates 2.09" (53mm) of rain.Snowfall
In Clay City, snow does not fall in May through September.Daylight
The average length of the day in September in Clay City is 12h and 25min.On the first day of September in Clay City, Illinois, sunrise is at 6:23 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:37 pm CDT.
Sunshine
The average sunshine in September in Clay City, Illinois, is 9.2h.UV index
The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: An average maximum UV index of 5 in September leads to these recommendations:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. Avoiding the Sun during its peak radiation time around midday is a healthy practice. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Clay City, IL
- Average high temperature in September: 78.6°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Clay City, 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 (29.93"Hg).
Average wind speed in September
Clay City, IL
- Average wind speed in September: 6.7mph
The windiest months (with the highest average wind speed) are January and February (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity in September
Clay City, IL
- Average humidity in September: 74%
The months with the highest relative humidity are May and July (80%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Clay City, IL
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is April (4.88").
The driest months (with the least rainfall) are February and September (2.09").
Average rainfall days in September
Clay City, IL
- Average rainfall days in September: 13.3 days
The month with the highest number of rainy days is May (19.9 days).
The month with the least rainy days is January (9.3 days).
Average snowfall in September
Clay City, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.05").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Clay City, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.1 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
Clay City, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 12min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in September
Clay City, IL
- Average sunshine days in September: 14.4 days
The month with the most sunshine days is October (17.5 days).
The month with the least sunshine days is May (9 days).
Average UV index in September
Clay City, 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, November and December (UV index 2).
Average cloud cover in September
Clay City, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is June (Cloud cover 28).
Average visibility in September
Clay City, 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).





