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	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		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					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	84		73			76			76					80	72	72
	Will	Braidwood
Metro-East	Jersey	Jerseyville	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