Fort Shaw, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 32.4 °F (low) to 58.2 °F (high). Annual precipitation averages 12.7 Inches. Fort Shaw is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.7 °F | 36.5 °F | 0.37 in. |
| February | 15.9 °F | 38.7 °F | 0.45 in. |
| March | 22.3 °F | 46.6 °F | 0.56 in. |
| April | 30.6 °F | 56.3 °F | 1.55 in. |
| May | 39.2 °F | 65.5 °F | 1.96 in. |
| June | 46.8 °F | 73.3 °F | 2.69 in. |
| July | 51.8 °F | 84.2 °F | 1.1 in. |
| August | 50.2 °F | 83.2 °F | 1.1 in. |
| September | 42.9 °F | 72.8 °F | 1.17 in. |
| October | 33.5 °F | 59.0 °F | 0.84 in. |
| November | 24.0 °F | 45.3 °F | 0.53 in. |
| December | 16.5 °F | 36.9 °F | 0.39 in. |
| Annual | 32.4 °F | 58.2 °F | 12.71 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |