Melba, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 39.6 °F (low) to 64.5 °F (high). Annual precipitation averages 9.8 Inches. Melba is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 24.5 °F | 39.3 °F | 1.13 in. |
| February | 27.6 °F | 46.5 °F | 0.84 in. |
| March | 32.8 °F | 56.2 °F | 1.06 in. |
| April | 37.1 °F | 63.1 °F | 1.0 in. |
| May | 44.8 °F | 72.2 °F | 1.32 in. |
| June | 51.6 °F | 80.8 °F | 0.76 in. |
| July | 58.8 °F | 91.3 °F | 0.22 in. |
| August | 56.9 °F | 89.8 °F | 0.2 in. |
| September | 48.5 °F | 80.0 °F | 0.46 in. |
| October | 38.5 °F | 65.5 °F | 0.7 in. |
| November | 30.1 °F | 50.1 °F | 0.93 in. |
| December | 24.4 °F | 39.4 °F | 1.2 in. |
| Annual | 39.6 °F | 64.5 °F | 9.82 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |