| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 6b: -5F to 0F |
| Average First Frost Date: | Oct. 21 - Oct. 31 |
| 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 46368 - Portage, IN | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 16 | 20 | 29 | 38 | 48 | 58 | 63 | 62 | 54 | 43 | 33 | 22 | 41 |
| Avg Max Temp (°F) | 32 | 37 | 48 | 59 | 71 | 81 | 84 | 82 | 76 | 65 | 50 | 37 | 60 |
| Avg Precip (In.) | 1.97 | 1.64 | 2.67 | 3.44 | 3.89 | 4.44 | 3.53 | 3.25 | 3.66 | 2.93 | 3.24 | 2.59 | 37.25 |