Illinois Ozone 8-hour Exceedance Summary

8-hour Exceedances Summary

Values in each column is 8-hour concentration - standard of 70 parts per billion;

Region	County	Site	10/3/25	10/1/25	9/19/25	9/18/25	9/17/25	9/12/25	9/10/25	8/16/25	8/6/25	8/5/25	7/29/25	7/22/25	7/15/25	7/14/25	7/3/25	7/2/25	6/16/25	6/12/25	6/11/25	6/7/25	6/5/25
Chicago Metropolitan	Cook	Alsip				74													71	71
	Cook	Chicago - Com Ed				76					73								71
	Cook	Chicago - SWFP	73		79	73		80		79	75	73	78		75	89		75	78		77
	Cook	Chicago - Taft				71					76		89			84	71		74		74
	Cook	Cicero									73					78			73		73
	Cook	Des Plaines									71		78			75
	Cook	Evanston	71		72			71					76		74	80		73	73		72
	Cook	Lemont				80	72					73
	Cook	Northbrook											82			77
	Cook	Schiller Park
	DuPage	Lisle										72
	Kane	Elgin				83	72												81	75		72
	Lake	Zion													71				73		71
	McHenry	Cary			72	84		73			76			76					80	72	72
	Will	Braidwood
Metro-East	Jersey	Jerseyville		71		88															76
	Madison	Alton				78
	Madison	Maryville							71
	Madison	Wood River				75
	Randolph	Houston
	St. Clair	East St. Louis
Northern Illinois	Rock Island	Rock Island
Northern Illinois	Winnebago	Loves Park				74														73
West Central Illinois	Adams	Quincy
	Macoupin	Nilwood					72
	Peoria	Peoria																					73
	Peoria	Peoria Heights																					73
	Sangamon	Springfield
East Central Illinois	Champaign	Thomasboro
	McLean	Normal																					74
	Macon	Decatur				72
Southeast Illinois	Effingham	Effingham
Southeast Illinois	Hamilton	Knight Prairie Township