Judith Gap, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 30.1 °F (low) to 55.9 °F (high). Annual precipitation averages 15.7 Inches. Judith Gap is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.6 °F | 36.0 °F | 0.46 in. |
| February | 14.3 °F | 37.0 °F | 0.46 in. |
| March | 20.6 °F | 44.8 °F | 0.63 in. |
| April | 27.7 °F | 52.8 °F | 1.57 in. |
| May | 36.0 °F | 61.8 °F | 2.91 in. |
| June | 44.0 °F | 70.3 °F | 3.08 in. |
| July | 49.7 °F | 81.2 °F | 1.92 in. |
| August | 48.3 °F | 81.0 °F | 1.46 in. |
| September | 40.6 °F | 70.3 °F | 1.38 in. |
| October | 30.4 °F | 56.8 °F | 0.86 in. |
| November | 21.3 °F | 43.5 °F | 0.5 in. |
| December | 14.6 °F | 35.4 °F | 0.46 in. |
| Annual | 30.1 °F | 55.9 °F | 15.69 in. |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | May 21 - May 31 |
| 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 | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |