| 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: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 43n - Central Grassland |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 59105 - Billings, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 13 | 18 | 25 | 33 | 43 | 51 | 56 | 55 | 45 | 35 | 23 | 15 | 34 |
| Avg Max Temp (°F) | 35 | 42 | 50 | 60 | 70 | 80 | 87 | 86 | 75 | 63 | 46 | 37 | 61 |
| Avg Precip (In.) | .72 | .52 | 1.01 | 1.65 | 2.43 | 1.89 | 1.22 | .9 | 1.37 | 1.28 | .7 | .62 | 14.3 |