| | Cahokia, IL | Union, MO | United States |
| Rainfall | 42.2 | 43.8 | 38.1 |
| Snowfall | 14.9 | 12.6 | 27.8 |
| Precipitation Days | 104.8 | 107.4 | 106.2 |
| Sunny | 202 | 200 | 205 |
| Avg. July High | 88.5 | 89 | 85.8 |
| Avg. Jan. Low | 22.6 | 21.7 | 21.7 |
| Comfort Index (higher=better) | 7.2 | 7.2 | 7 |
| UV Index | 4.1 | 4.1 | 4.3 |
| Elevation ft. | 407 | 528 | 2443 |