Busby, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -0.7 °C (low) to 15.7 °C (high). Annual precipitation averages 401.1 Millimeters. Busby is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.3 °C | 1.9 °C | 17.53 mm |
| February | -10.7 °C | 3.5 °C | 17.78 mm |
| March | -5.8 °C | 9.5 °C | 24.38 mm |
| April | -1.2 °C | 14.7 °C | 42.93 mm |
| May | 3.8 °C | 19.7 °C | 69.6 mm |
| June | 8.7 °C | 25.4 °C | 54.36 mm |
| July | 11.9 °C | 31.2 °C | 36.32 mm |
| August | 10.6 °C | 30.9 °C | 25.15 mm |
| September | 5.6 °C | 24.8 °C | 39.88 mm |
| October | -0.7 °C | 16.1 °C | 38.35 mm |
| November | -6.7 °C | 8.3 °C | 18.03 mm |
| December | -11.6 °C | 2.5 °C | 16.76 mm |
| Annual | -0.7 °C | 15.7 °C | 401.07 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |