Inverness, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 29.8 °F (low) to 55.9 °F (high). Annual precipitation averages 10.8 Inches. Inverness is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 8.3 °F | 30.6 °F | 0.36 in. |
| February | 10.7 °F | 33.9 °F | 0.28 in. |
| March | 19.1 °F | 43.3 °F | 0.35 in. |
| April | 29.1 °F | 55.3 °F | 0.81 in. |
| May | 38.6 °F | 65.4 °F | 1.62 in. |
| June | 46.7 °F | 73.3 °F | 2.54 in. |
| July | 52.2 °F | 83.1 °F | 1.19 in. |
| August | 50.7 °F | 82.8 °F | 1.05 in. |
| September | 41.9 °F | 71.9 °F | 1.08 in. |
| October | 30.4 °F | 57.1 °F | 0.68 in. |
| November | 19.5 °F | 41.8 °F | 0.52 in. |
| December | 10.8 °F | 32.3 °F | 0.32 in. |
| Annual | 29.8 °F | 55.9 °F | 10.8 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 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 |