Geographical distribution of Illinois glaze storms.
| Areas | Nov | Dec | Jan | Feb | Mar | Apr | Total |
|---|---|---|---|---|---|---|---|
| North | 1 | 1 | 1 | 2 | 6 | 2 | 13 |
| Central | 1 | 5 | 5 | 2 | 3 | 2 | 18 |
| South | 0 | 4 | 2 | 4 | 2 | 0 | 12 |
| North + Central | 0 | 3 | 5 | 4 | 4 | 0 | 16 |
| Central + South | 0 | 2 | 7 | 2 | 1 | 0 | 12 |
| North + Central + South | 1 | 7 | 7 | 4 | 2 | 0 | 21 |