| 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 5b: -15°F to -10°F Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F | |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F | |
| Average First Frost Date: | Sep.1 - Sep. 10 | |
| Average Last Frost Date: | Jun. 1 - Jun. 10 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 17b - The Black Hills Plateau | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 57730 - Custer, SD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 12 | 16 | 20 | 28 | 37 | 46 | 52 | 50 | 41 | 31 | 21 | 14 | 31 |
| Avg Max Temp (°F) | 35 | 40 | 45 | 53 | 63 | 73 | 80 | 79 | 70 | 59 | 44 | 37 | 57 |
| Avg Precip (In.) | .38 | .61 | 1.06 | 2.07 | 3.27 | 3.24 | 3.1 | 2.33 | 1.5 | 1.44 | .67 | .51 | 20.18 |