| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 50ag - Newaygo Barrens |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 49644 - Irons, MI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 12 | 20 | 31 | 42 | 50 | 55 | 53 | 46 | 36 | 28 | 18 | 33 |
| Avg Max Temp (°F) | 28 | 32 | 42 | 55 | 69 | 77 | 81 | 79 | 71 | 59 | 44 | 33 | 56 |
| Avg Precip (In.) | 2.2 | 1.51 | 2.13 | 2.76 | 2.9 | 3.26 | 2.96 | 3.86 | 3.88 | 3.31 | 2.96 | 2.32 | 34.05 |