Weather in September in Ottawa, Il

< September >
	Normal Max/ High Temperature	25°C (77°F)
	Average Temperature	19°C (66°F)
	Min/ Low Temperature	13°C (55°F)
	Normal Precipitation	98mm (3.9in)
	Average Daylight per day	12h 25'
	Sun altitude at solar noon on the 21st day.	49.5°

• The average temperature in Ottawa, Il in September is somewhat warm at 18.8 °C (65.84 °F).
• Afternoons can be fairly hot with average high temperatures reaching 25.1 °C (77.2 °F).
• Overnight temperatures are generally mild with an average low of 12.6 °C (54.7 °F).
• In September the variation/ range of diurnal mean temperatures is 12.5 °C (22.5 °F).
• Precipitation averages for September are high with 98mm (3.9 in) recorded.
• The shortest day is 11h 45' long and the longest day is 13h 05' long with an average length of 12h 25'.

Weather Trend Graph for September in Ottawa, Il, Usa