Whitlash, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -0.4 °C (low) to 12.6 °C (high). Annual precipitation averages 427.2 Millimeters. Whitlash is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.8 °C | 1.9 °C | 15.24 mm |
| February | -9.7 °C | 2.2 °C | 12.45 mm |
| March | -6.2 °C | 6.1 °C | 19.3 mm |
| April | -1.3 °C | 11.2 °C | 37.85 mm |
| May | 3.8 °C | 16.5 °C | 61.47 mm |
| June | 7.5 °C | 20.6 °C | 94.49 mm |
| July | 10.8 °C | 26.1 °C | 39.37 mm |
| August | 10.3 °C | 26.2 °C | 42.16 mm |
| September | 6 °C | 20.3 °C | 42.67 mm |
| October | 0.2 °C | 12.8 °C | 29.72 mm |
| November | -5.8 °C | 5.8 °C | 18.03 mm |
| December | -9.7 °C | 2 °C | 14.48 mm |
| Annual | -0.4 °C | 12.6 °C | 427.23 mm |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 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 |