Glenns Ferry, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 37.9 °F (low) to 67.2 °F (high). Annual precipitation averages 9.3 Inches. Glenns Ferry is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.7 °F | 40.8 °F | 1.64 in. |
| February | 25.8 °F | 47.7 °F | 0.68 in. |
| March | 31.2 °F | 57.5 °F | 0.86 in. |
| April | 35.9 °F | 65.1 °F | 0.74 in. |
| May | 44.0 °F | 75.2 °F | 0.92 in. |
| June | 50.5 °F | 84.6 °F | 0.54 in. |
| July | 57.2 °F | 96.1 °F | 0.17 in. |
| August | 54.7 °F | 94.3 °F | 0.23 in. |
| September | 45.5 °F | 83.5 °F | 0.26 in. |
| October | 35.2 °F | 68.4 °F | 0.69 in. |
| November | 27.6 °F | 51.9 °F | 0.91 in. |
| December | 22.9 °F | 40.7 °F | 1.68 in. |
| Annual | 37.9 °F | 67.2 °F | 9.32 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |