Melstone, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 33.5 °F (low) to 60.6 °F (high). Annual precipitation averages 15.2 Inches. Melstone is located in USDA Plant Hardiness Zone 4b. 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 | 12.5 °F | 35.3 °F | 0.5 in. |
| February | 15.1 °F | 38.9 °F | 0.49 in. |
| March | 23.4 °F | 49.2 °F | 0.78 in. |
| April | 32.2 °F | 59.3 °F | 1.61 in. |
| May | 41.7 °F | 68.4 °F | 2.53 in. |
| June | 50.4 °F | 78.1 °F | 2.94 in. |
| July | 56.6 °F | 88.4 °F | 1.61 in. |
| August | 54.6 °F | 87.7 °F | 1.14 in. |
| September | 44.9 °F | 76.6 °F | 1.17 in. |
| October | 33.7 °F | 61.3 °F | 1.28 in. |
| November | 22.9 °F | 47.0 °F | 0.57 in. |
| December | 14.2 °F | 36.7 °F | 0.55 in. |
| Annual | 33.5 °F | 60.6 °F | 15.17 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 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |