West Havre, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -0.7 °C (low) to 13.6 °C (high). Annual precipitation averages 311.7 Millimeters. West Havre 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 | -13.7 °C | -2.1 °C | 10.92 mm |
| February | -12.2 °C | 0.2 °C | 8.64 mm |
| March | -6.8 °C | 6.4 °C | 12.45 mm |
| April | -0.8 °C | 13.7 °C | 29.46 mm |
| May | 4.7 °C | 19.2 °C | 45.97 mm |
| June | 9.4 °C | 23.8 °C | 67.06 mm |
| July | 12.4 °C | 29.5 °C | 40.13 mm |
| August | 11.3 °C | 29.1 °C | 23.88 mm |
| September | 6.1 °C | 22.8 °C | 27.69 mm |
| October | -0.5 °C | 14.3 °C | 20.32 mm |
| November | -6.6 °C | 5.7 °C | 15.49 mm |
| December | -11.9 °C | 0.1 °C | 9.65 mm |
| Annual | -0.7 °C | 13.6 °C | 311.66 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| 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 |