Plentywood, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 27.5 °F (low) to 52.9 °F (high). Annual precipitation averages 14.8 Inches. Plentywood is located in USDA Plant Hardiness Zone 3b. 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 | -1.0 °F | 20.7 °F | 0.43 in. |
| February | 4.1 °F | 26.1 °F | 0.37 in. |
| March | 15.5 °F | 37.9 °F | 0.65 in. |
| April | 27.6 °F | 54.4 °F | 1.06 in. |
| May | 39.0 °F | 66.7 °F | 1.76 in. |
| June | 49.4 °F | 74.9 °F | 3.17 in. |
| July | 53.7 °F | 82.1 °F | 2.68 in. |
| August | 51.4 °F | 82.6 °F | 1.39 in. |
| September | 41.2 °F | 71.5 °F | 1.28 in. |
| October | 28.8 °F | 54.9 °F | 0.94 in. |
| November | 15.9 °F | 37.3 °F | 0.54 in. |
| December | 4.8 °F | 25.2 °F | 0.48 in. |
| Annual | 27.5 °F | 52.9 °F | 14.75 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 3b : -35°F to -30°F |
| Plant Hardiness Zone - 2012 | Zone 3b : -35°F to -30°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |