Yaak, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 28.4 °F (low) to 55.4 °F (high). Annual precipitation averages 26 Inches. Yaak is located in USDA Plant Hardiness Zone 5a. 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 | 15.1 °F | 30.6 °F | 2.85 in. |
| February | 14.7 °F | 37.6 °F | 2.0 in. |
| March | 21.6 °F | 46.0 °F | 2.51 in. |
| April | 26.8 °F | 55.2 °F | 1.64 in. |
| May | 34.2 °F | 65.8 °F | 2.22 in. |
| June | 40.5 °F | 71.9 °F | 2.51 in. |
| July | 43.9 °F | 82.4 °F | 1.12 in. |
| August | 42.4 °F | 82.6 °F | 0.81 in. |
| September | 35.6 °F | 71.2 °F | 1.43 in. |
| October | 28.3 °F | 54.5 °F | 2.49 in. |
| November | 22.2 °F | 38.2 °F | 3.2 in. |
| December | 15.9 °F | 29.1 °F | 3.22 in. |
| Annual | 28.4 °F | 55.4 °F | 26 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |