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 |
| Chicago Metropolitan | Cook | Alsip | |
| Cook | Chicago-Com Ed | ||
| Cook | Chicago-Springfield Pump | ||
| Cook | Chicago-Mayfair | ||
| Cook | Chicago-Washington HS | ||
| Cook | Cicero | ||
| Cook | Des Plaines | ||
| Cook | Kingery Near-Road | ||
| Cook | McCook | ||
| Cook | Northbrook | ||
| Cook | Schiller Park | ||
| Cook | Summit | ||
| Du Page | Naperville | ||
| Kane | Aurora | ||
| Kane | Elgin | ||
| McHenry | Cary | ||
| Will | Braidwood | ||
| Will | Joliet | ||
| 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 | |
| Sangamon | Springfield | ||
| East Central Illinois | Champaign | Bondville | 39.5 |
| Champaign | Champaign | 50.0 | |
| Macon | Decatur | 51.6 | |
| McLean | Normal | ||
| Southeast Illinois | Hamilton | Knight Prairie |