Illinois
| Site | Code |
|---|
| ALTON/ST LOUIS RGNL | KALN |
| AURORA MUNICIPAL | KARR |
| SCOTT AFB/BELLEVILL | KBLV |
| BLOOMINGTON/NORMAL | KBMI |
| CHICAGO/MEIGS | KCGX |
| CHAMPAIGN/URBANA | KCMI |
| CAHOKIA/ST. LOUIS | KCPS |
| DECATUR AIRPORT | KDEC |
| W. CHICAGO/DU PAGE | KDPA |
| CARBONDALE/MURPHYSB | KMDH |
| CHICAGO/MIDWAY | KMDW |
| MOLINE/QUAD CITY | KMLI |
| MARSEILLES (AMOS) | KMMO |
| MOUNT VERNON (AWOS) | KMVN |
| MARION REGIONAL | KMWA |
| CHICAGO/O'HARE ARPT | KORD |
| PEORIA REGIONAL | KPIA |
| CHICAGO/PALWAUKEE | KPWK |
| ROCKFORD | KRFD |
| SPRINGFIELD/CAPITAL | KSPI |
| STERLING ROCKFALLS | KSQI |
| CHICAGO/WAUKEGAN | KUGN |
| QUINCY MUNI/BALDWIN | KUIN |