Weather in September in Mt Vernon, Il

< September >
	Normal Max/ High Temperature	27°C (80°F)
	Average Temperature	20°C (68°F)
	Min/ Low Temperature	13°C (56°F)
	Normal Precipitation	83mm (3.3in)
	Average Daylight per day	12h 23'
	Sun altitude at solar noon on the 21st day.	52.5°

• The average temperature in Mt Vernon, Il in September is warm at 20 °C (68 °F).
• Afternoons can be hot with average high temperatures reaching 26.6 °C (79.9 °F).
• Overnight temperatures are generally mild with an average low of 13.3 °C (55.9 °F).
• In September there is a variation/ range of mean diurnal temperatures of 13.3 °C (23.9 °F).
• Precipitation averages for September are high with 83.3mm (3.3 in) recorded.
• The shortest day is 11h 46' long and the longest day is 12h 59' long with an average length of 12h 23'.

Weather Trend Graph for September in Mt Vernon, Il, Usa