| 2023 Hardiness Zone: | Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 1990 Hardiness Zone: | Zone 6b: -5F to 0F |
| Average First Frost Date: | Oct. 21 - Oct. 31 |
| Average Last Frost Date: | Apr. 11 - Apr. 20 |
| Koppen-Geiger Climate Zone: | Cfa - Humid Subtropical Climate |
| Ecoregion: | 72a - Wabash-Ohio Bottomlands |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 47620 - Mount Vernon, IN | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 23 | 26 | 36 | 45 | 55 | 64 | 68 | 65 | 58 | 46 | 37 | 27 | 46 |
| Avg Max Temp (°F) | 39 | 44 | 55 | 66 | 76 | 85 | 88 | 87 | 81 | 69 | 56 | 44 | 66 |
| Avg Precip (In.) | 3.3 | 3.17 | 4.52 | 4.36 | 5.24 | 4.03 | 4.07 | 3.07 | 2.76 | 2.92 | 4.32 | 3.66 | 45.41 |