Judith Gap, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -1.1 °C (low) to 13.3 °C (high). Annual precipitation averages 398.5 Millimeters. 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 | -10.2 °C | 2.2 °C | 11.68 mm |
| February | -9.8 °C | 2.8 °C | 11.68 mm |
| March | -6.3 °C | 7.1 °C | 16 mm |
| April | -2.4 °C | 11.6 °C | 39.88 mm |
| May | 2.2 °C | 16.6 °C | 73.91 mm |
| June | 6.7 °C | 21.3 °C | 78.23 mm |
| July | 9.8 °C | 27.3 °C | 48.77 mm |
| August | 9.1 °C | 27.2 °C | 37.08 mm |
| September | 4.8 °C | 21.3 °C | 35.05 mm |
| October | -0.9 °C | 13.8 °C | 21.84 mm |
| November | -5.9 °C | 6.4 °C | 12.7 mm |
| December | -9.7 °C | 1.9 °C | 11.68 mm |
| Annual | -1.1 °C | 13.3 °C | 398.5 mm |
| 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 : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |