Carter, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Annual precipitation averages 334.5 Millimeters. 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 | -11.1 °C | 1.1 °C | 11.68 mm |
| February | -10.1 °C | 2.8 °C | 10.41 mm |
| March | -5.9 °C | 7.9 °C | 13.21 mm |
| April | -0.7 °C | 13.9 °C | 37.08 mm |
| May | 4.4 °C | 18.9 °C | 53.34 mm |
| June | 8.8 °C | 23.5 °C | 68.33 mm |
| July | 11.9 °C | 29.4 °C | 30.23 mm |
| August | 11 °C | 29.2 °C | 29.97 mm |
| September | 6.4 °C | 23.1 °C | 29.97 mm |
| October | 0.3 °C | 15.1 °C | 25.15 mm |
| November | -5.2 °C | 7.2 °C | 14.48 mm |
| December | -9.8 °C | 1.9 °C | 10.67 mm |
| Annual | 0 °C | 14.5 °C | 334.52 mm |
| 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 : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |