| 2023 Hardiness Zone: | Zone 3b: -35°F to -30°F Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F | |
| 2012 Hardiness Zone: | Zone 3b: -35°F to -30°F Zone 4a: -30°F to -25°F | |
| 1990 Hardiness Zone: | Zone 3b: -35F to -30F | |
| Average First Frost Date: | Sep. 21 - Sep. 30 | |
| Average Last Frost Date: | May 21 - May 31 | |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate | |
| Ecoregion: | 43c - River Breaks | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 58801 - Williston, ND | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | -2 | 7 | 18 | 30 | 42 | 51 | 56 | 54 | 43 | 31 | 16 | 3 | 29 |
| Avg Max Temp (°F) | 20 | 28 | 41 | 56 | 69 | 78 | 84 | 83 | 71 | 58 | 37 | 24 | 54 |
| Avg Precip (In.) | .52 | .38 | .72 | 1.07 | 1.93 | 2.43 | 2.3 | 1.5 | 1.39 | .88 | .62 | .55 | 14.28 |