| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | Apr. 11 - Apr. 20 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 72j - Southern Illinoian Till Plain |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 62828 - Dahlgren, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 20 | 24 | 34 | 44 | 53 | 62 | 66 | 64 | 56 | 44 | 35 | 25 | 44 |
| Avg Max Temp (°F) | 38 | 44 | 55 | 66 | 76 | 85 | 89 | 87 | 81 | 69 | 55 | 43 | 66 |
| Avg Precip (In.) | 2.79 | 2.68 | 4.06 | 4.43 | 4.65 | 3.91 | 3.61 | 3.1 | 3 | 3.02 | 4.3 | 3.48 | 43.01 |