Carter, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 32 °F (low) to 58.1 °F (high). Annual precipitation averages 13.2 Inches. Carter 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. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.1 °F | 33.9 °F | 0.46 in. |
| February | 13.8 °F | 37.1 °F | 0.41 in. |
| March | 21.4 °F | 46.2 °F | 0.52 in. |
| April | 30.8 °F | 57.0 °F | 1.46 in. |
| May | 40.0 °F | 66.1 °F | 2.1 in. |
| June | 47.9 °F | 74.3 °F | 2.69 in. |
| July | 53.4 °F | 85.0 °F | 1.19 in. |
| August | 51.8 °F | 84.5 °F | 1.18 in. |
| September | 43.5 °F | 73.6 °F | 1.18 in. |
| October | 32.5 °F | 59.1 °F | 0.99 in. |
| November | 22.6 °F | 44.9 °F | 0.57 in. |
| December | 14.3 °F | 35.4 °F | 0.42 in. |
| Annual | 32 °F | 58.1 °F | 13.17 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 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 |