| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F |
| 1990 Hardiness Zone: | Zone 4a: -30F to -25F |
| Average First Frost Date: | Sep.11 - Sep. 20 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 43o - Unglaciated Montana High Plains |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 59019 - Columbus, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 15 | 23 | 31 | 39 | 47 | 52 | 51 | 41 | 31 | 21 | 13 | 31 |
| Avg Max Temp (°F) | 36 | 42 | 50 | 59 | 69 | 78 | 85 | 85 | 74 | 62 | 45 | 37 | 60 |
| Avg Precip (In.) | .69 | .6 | 1.09 | 1.86 | 2.9 | 1.91 | 1.33 | 1.06 | 1.45 | 1.32 | .68 | .65 | 15.55 |