September weather forecastMount Erie, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Mount Erie, Illinois, with temperature in the range of an average high of 79°F (26.1°C) and an average low of 60.4°F (15.8°C).Temperature
The arrival of September marks a slight shift to an average high-temperature of a still moderately hot 79°F (26.1°C) from August's 83.8°F (28.8°C). Throughout September, Mount Erie records an average temperature of 60.4°F (15.8°C) at night.Humidity
In Mount Erie, the average relative humidity in September is 74%.Rainfall
September is the month with the least rainfall. Rain falls for 13.5 days and accumulates 2.05" (52mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
The average length of the day in September in Mount Erie is 12h and 25min.On the first day of September, sunrise is at 6:22 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:36 pm CDT.
Sunshine
The average sunshine in September is 9.1h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: An average maximum UV index of 5 in September leads to these recommendations:
Exercise prevention - Protecting skin and eyes from harm is required. To protect against the Sun's most potent rays, avoid direct exposure around midday. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mount Erie, IL
- Average high temperature in September: 79°F
The warmest month (with the highest average high temperature) is July (85.1°F).
The month with the lowest average high temperature is January (37.8°F).
- Average low temperature in September: 60.4°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (25°F).
Average pressure in September
Mount Erie, 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
Mount Erie, IL
- Average wind speed in September: 6.7mph
The windiest months (with the highest average wind speed) are February and March (9.9mph).
The calmest month (with the lowest average wind speed) is July (5.9mph).
Average humidity in September
Mount Erie, IL
- Average humidity in September: 74%
The months with the highest relative humidity are May and July (79%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Mount Erie, IL
- Average rainfall in September: 2.05"
The wettest month (with the highest rainfall) is April (4.96").
The driest month (with the least rainfall) is September (2.05").
Average rainfall days in September
Mount Erie, IL
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is May (19.8 days).
The month with the least rainy days is January (8.7 days).
Average snowfall in September
Mount Erie, IL
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (2.01").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Mount Erie, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.7 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
Mount Erie, 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 6min
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
Mount Erie, IL
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is October (17.9 days).
The month with the least sunshine days is May (9 days).
Average UV index in September
Mount Erie, 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
Mount Erie, IL
- Average cloud cover in September: 29
The months with the most cloud cover are January and February (Cloud cover 51).
The months with the least cloud cover are June and August (Cloud cover 28).
Average visibility in September
Mount Erie, 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).





