Heart Butte, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 30.3 °F (low) to 52.5 °F (high). Annual precipitation averages 17.6 Inches. Heart Butte is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.4 °F | 33.4 °F | 0.81 in. |
| February | 14.9 °F | 34.6 °F | 0.94 in. |
| March | 20.6 °F | 41.0 °F | 1.03 in. |
| April | 28.0 °F | 48.9 °F | 1.65 in. |
| May | 36.0 °F | 58.6 °F | 2.4 in. |
| June | 42.8 °F | 66.3 °F | 3.33 in. |
| July | 48.4 °F | 77.2 °F | 1.42 in. |
| August | 47.1 °F | 76.7 °F | 1.26 in. |
| September | 40.0 °F | 66.1 °F | 1.47 in. |
| October | 31.2 °F | 52.9 °F | 1.33 in. |
| November | 23.6 °F | 40.9 °F | 1.1 in. |
| December | 16.6 °F | 33.6 °F | 0.84 in. |
| Annual | 30.3 °F | 52.5 °F | 17.58 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | Over 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 | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |