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	7/17/26	7/16/26	7/15/26	7/14/26	7/13/26	7/8/26	7/7/26	6/6/26	6/4/26	6/3/26	5/30/26	5/29/26	5/27/26	5/26/26	5/25/26	5/16/26
Chicago Metropolitan	Cook	Alsip		83		78	80
	Cook	Chicago - Com Ed		71	81	89	78
	Cook	Chicago - SWFP		75	75	84	72	80			71			80	72		77
	Cook	Chicago - Taft			74	97	75	78			74
	Cook	Cicero				91	75	73
	Cook	Des Plaines				82		73						71
	Cook	Evanston	78		73	94	75	91			76			77			76	72
	Cook	Lemont		93		74			73						79
	Cook	Northbrook				72		79			77			77			74	75
	Cook	Schiller Park				78
	DuPage	Lisle		87					72		71			75	77
	Kane	Elgin									71			73	73	73
	Lake	Zion			75			89		71	78						78	79
	McHenry	Cary		76							74	73		77	73	77	71	75
	Will	Braidwood													90
Metro-East	Jersey	Jerseyville
	Madison	Alton
	Madison	Maryville
	Madison	Wood River
	Randolph	Houston
	St. Clair	East St. Louis
Northern Illinois	Rock Island	Rock Island											78		76
Northern Illinois	Winnebago	Loves Park													73	72		73
West Central Illinois	Adams	Quincy
	Macoupin	Nilwood
	Peoria	Peoria											74		77
	Peoria	Peoria Heights											72
	Sangamon	Springfield
East Central Illinois	Champaign	Thomasboro
	McLean	Normal											74
	Macon	Decatur
Southeast Illinois	Effingham	Effingham
Southeast Illinois	Hamilton	Knight Prairie Township