Colstrip, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 33 °F (low) to 59 °F (high). Annual precipitation averages 16.4 Inches. 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 | 12.0 °F | 35.2 °F | 0.62 in. |
| February | 14.4 °F | 37.9 °F | 0.69 in. |
| March | 23.2 °F | 48.1 °F | 0.96 in. |
| April | 31.6 °F | 56.4 °F | 1.9 in. |
| May | 40.9 °F | 65.7 °F | 3.22 in. |
| June | 50.0 °F | 76.0 °F | 2.48 in. |
| July | 56.4 °F | 86.1 °F | 1.34 in. |
| August | 54.2 °F | 85.2 °F | 1.03 in. |
| September | 44.8 °F | 74.6 °F | 1.46 in. |
| October | 33.0 °F | 59.5 °F | 1.45 in. |
| November | 22.4 °F | 46.3 °F | 0.7 in. |
| December | 13.4 °F | 36.4 °F | 0.55 in. |
| Annual | 33 °F | 59 °F | 16.4 in. |
| 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 : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |