Illinois Environmental Protection Agency

Illinois PM2.5 24-hour Exceedance Summary

Value in each column is 24-hour concentration - standard of 35 micrograms per cubic meter

(values in micrograms per cubic meter)

Region  County Site 3/15/25  6/4/25  6/5/25  6/6/25  6/7/25 
Chicago Metropolitan  Cook Alsip     49.0  37.2   
Cook Chicago-Com Ed     43.8     
Cook Chicago-Springfield Pump     58.9     
Cook Chicago-Mayfair     59.5  35.0   
Cook Chicago-Washington HS   43.5  59.3  36.8   
Cook Cicero     58.2  37.8   
Cook Des Plaines     55.3     
Cook Kingery Near-Road     53.9  35.4   
Cook McCook          
Cook Northbrook     46.0     
Cook Schiller Park     59.2     
Cook Summit     53.3  39.9   
Du Page Naperville     51.1  35.7   
Kane Aurora     46.3     
Kane Elgin     48.4     
McHenry Cary     45.2     
Will Braidwood     47.5  42.3  37.7 
Will Joliet     48.6  42.8   
Metro-East  Jersey Jerseyville          
Madison Alton 57.7         
Madison Granite City Fire Station 65.0         
Madison Granite City-Gateway Medical 62.6         
Madison Wood River 51.9         
Randolph Houston 69.3         
St Clair E St. Louis 69.3         
Northern Illinois  Rock Island Rock Island          
Winnebago Rockford          
West Central Illinois  Peoria Peoria     44.2  40.2   
Sangamon Springfield       36.3   
East Central Illinois  Champaign Bondville 39.5         
Champaign Champaign 50.0         
Macon Decatur 51.6         
McLean Normal     43.8     
Southeast Illinois  Hamilton Knight Prairie