| 2023 Hardiness Zone: | 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 4b: -25°F to -20°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F | |
| Average First Frost Date: | Oct. 1 - Oct. 10 | |
| Average Last Frost Date: | May 21 - May 31 | |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate | |
| Ecoregion: | 17a - Black Hills Plateau | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 57783 - Spearfish, SD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 12 | 16 | 22 | 32 | 42 | 51 | 57 | 55 | 45 | 34 | 23 | 15 | 34 |
| Avg Max Temp (°F) | 35 | 39 | 46 | 56 | 66 | 76 | 83 | 83 | 72 | 59 | 43 | 37 | 58 |
| Avg Precip (In.) | .59 | .7 | 1.44 | 2.52 | 3.65 | 3.91 | 2.25 | 1.74 | 1.49 | 2.14 | 1 | .74 | 22.15 |