Clark Fork, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 35.3 °F (low) to 57.2 °F (high). Annual precipitation averages 31.1 Inches. Clark Fork is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.3 °F | 34.2 °F | 3.92 in. |
| February | 23.6 °F | 38.8 °F | 2.53 in. |
| March | 27.9 °F | 47.4 °F | 3.06 in. |
| April | 33.2 °F | 56.6 °F | 2.23 in. |
| May | 40.1 °F | 66.8 °F | 2.82 in. |
| June | 46.2 °F | 72.6 °F | 2.83 in. |
| July | 50.1 °F | 82.9 °F | 0.99 in. |
| August | 49.1 °F | 83.1 °F | 0.84 in. |
| September | 42.3 °F | 72.3 °F | 1.32 in. |
| October | 34.8 °F | 56.3 °F | 2.81 in. |
| November | 29.0 °F | 41.7 °F | 3.81 in. |
| December | 23.5 °F | 33.7 °F | 3.94 in. |
| Annual | 35.3 °F | 57.2 °F | 31.1 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |