Miles City, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.6 °C (low) to 15.7 °C (high). Annual precipitation averages 372.4 Millimeters. Miles City is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -13 °C | -0.2 °C | 12.45 mm |
| February | -10.9 °C | 2.4 °C | 12.19 mm |
| March | -5.4 °C | 9.2 °C | 21.59 mm |
| April | 0.4 °C | 15.3 °C | 36.58 mm |
| May | 6 °C | 20.8 °C | 68.07 mm |
| June | 11.3 °C | 26.6 °C | 64.26 mm |
| July | 14.6 °C | 32.1 °C | 45.21 mm |
| August | 13.3 °C | 31.3 °C | 25.65 mm |
| September | 7.7 °C | 25.2 °C | 30.23 mm |
| October | 0.9 °C | 16.2 °C | 29.46 mm |
| November | -6 °C | 7.8 °C | 13.97 mm |
| December | -11.5 °C | 1.3 °C | 12.7 mm |
| Annual | 0.6 °C | 15.7 °C | 372.36 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 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 |