| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 1 - May 10 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 54b - Chicago Lake Plain |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 46319 - Griffith, IN | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 19 | 29 | 39 | 49 | 59 | 64 | 62 | 54 | 43 | 32 | 21 | 40 |
| Avg Max Temp (°F) | 31 | 36 | 47 | 58 | 70 | 80 | 84 | 82 | 75 | 64 | 49 | 36 | 59 |
| Avg Precip (In.) | 1.91 | 1.6 | 2.71 | 3.63 | 3.93 | 4.41 | 3.67 | 3.72 | 3.58 | 2.95 | 3.4 | 2.6 | 38.12 |