Gannett, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 30.2 °F (low) to 58.1 °F (high). Annual precipitation averages 12.3 Inches. Gannett is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 10.9 °F | 31.8 °F | 1.65 in. |
| February | 14.0 °F | 36.1 °F | 1.15 in. |
| March | 22.3 °F | 45.7 °F | 1.27 in. |
| April | 29.5 °F | 56.3 °F | 1.09 in. |
| May | 37.3 °F | 66.0 °F | 1.39 in. |
| June | 43.2 °F | 75.2 °F | 0.83 in. |
| July | 50.4 °F | 86.7 °F | 0.28 in. |
| August | 49.0 °F | 85.7 °F | 0.32 in. |
| September | 41.1 °F | 75.6 °F | 0.54 in. |
| October | 30.8 °F | 60.9 °F | 0.99 in. |
| November | 21.3 °F | 44.4 °F | 1.0 in. |
| December | 12.6 °F | 32.3 °F | 1.77 in. |
| Annual | 30.2 °F | 58.1 °F | 12.28 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |