Wilsall, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 28.8 °F (low) to 56.4 °F (high). Annual precipitation averages 15.1 Inches. Wilsall is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.9 °F | 34.9 °F | 0.55 in. |
| February | 14.5 °F | 36.5 °F | 0.45 in. |
| March | 21.0 °F | 44.9 °F | 0.88 in. |
| April | 27.2 °F | 54.1 °F | 1.45 in. |
| May | 34.9 °F | 62.6 °F | 2.46 in. |
| June | 42.0 °F | 72.0 °F | 2.68 in. |
| July | 47.2 °F | 82.7 °F | 1.39 in. |
| August | 45.2 °F | 82.7 °F | 1.11 in. |
| September | 38.1 °F | 71.8 °F | 1.43 in. |
| October | 29.0 °F | 57.6 °F | 1.24 in. |
| November | 20.0 °F | 42.7 °F | 0.78 in. |
| December | 13.2 °F | 33.8 °F | 0.72 in. |
| Annual | 28.8 °F | 56.4 °F | 15.14 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |