| 2023 Hardiness Zone: | Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F | |
| 2012 Hardiness Zone: | Zone 4a: -30°F to -25°F | |
| 1990 Hardiness Zone: | Zone 3b: -35F to -30F | |
| Average First Frost Date: | Sep.11 - Sep. 20 | |
| 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: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 59270 - Sidney, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 2 | 10 | 20 | 31 | 43 | 51 | 55 | 54 | 44 | 33 | 19 | 7 | 31 |
| Avg Max Temp (°F) | 24 | 32 | 45 | 60 | 72 | 80 | 86 | 86 | 74 | 60 | 40 | 28 | 57 |
| Avg Precip (In.) | .4 | .35 | .57 | 1.08 | 2.03 | 2.77 | 2.13 | 1.31 | 1.5 | 1.02 | .61 | .47 | 14.23 |