Salmon, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 32 °F (low) to 58.5 °F (high). Annual precipitation averages 9.3 Inches. Salmon is located in USDA Plant Hardiness Zone 5b. 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 | 14.0 °F | 30.7 °F | 0.55 in. |
| February | 17.2 °F | 37.3 °F | 0.41 in. |
| March | 25.8 °F | 49.9 °F | 0.55 in. |
| April | 31.7 °F | 59.0 °F | 0.74 in. |
| May | 39.1 °F | 68.3 °F | 1.34 in. |
| June | 45.5 °F | 76.2 °F | 1.43 in. |
| July | 51.0 °F | 87.3 °F | 0.68 in. |
| August | 48.8 °F | 85.8 °F | 0.59 in. |
| September | 41.1 °F | 75.5 °F | 0.78 in. |
| October | 31.8 °F | 59.2 °F | 0.88 in. |
| November | 23.0 °F | 42.0 °F | 0.64 in. |
| December | 14.4 °F | 30.4 °F | 0.73 in. |
| Annual | 32 °F | 58.5 °F | 9.32 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |