Colstrip, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.6 °C (low) to 15 °C (high). Annual precipitation averages 416.6 Millimeters. Colstrip is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.1 °C | 1.8 °C | 15.75 mm |
| February | -9.8 °C | 3.3 °C | 17.53 mm |
| March | -4.9 °C | 8.9 °C | 24.38 mm |
| April | -0.2 °C | 13.6 °C | 48.26 mm |
| May | 4.9 °C | 18.7 °C | 81.79 mm |
| June | 10 °C | 24.4 °C | 62.99 mm |
| July | 13.6 °C | 30.1 °C | 34.04 mm |
| August | 12.3 °C | 29.6 °C | 26.16 mm |
| September | 7.1 °C | 23.7 °C | 37.08 mm |
| October | 0.6 °C | 15.3 °C | 36.83 mm |
| November | -5.3 °C | 7.9 °C | 17.78 mm |
| December | -10.3 °C | 2.4 °C | 13.97 mm |
| Annual | 0.6 °C | 15 °C | 416.56 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |