Plummer, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 35.3 °F (low) to 57.6 °F (high). Annual precipitation averages 29.3 Inches. Plummer is located in USDA Plant Hardiness Zone 6b. 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 | 24.3 °F | 36.0 °F | 3.78 in. |
| February | 24.8 °F | 39.8 °F | 2.96 in. |
| March | 28.7 °F | 47.7 °F | 3.22 in. |
| April | 33.5 °F | 55.8 °F | 2.46 in. |
| May | 39.9 °F | 65.4 °F | 2.45 in. |
| June | 45.3 °F | 71.2 °F | 1.94 in. |
| July | 49.7 °F | 82.5 °F | 0.77 in. |
| August | 49.1 °F | 83.4 °F | 0.76 in. |
| September | 42.0 °F | 73.4 °F | 0.99 in. |
| October | 34.6 °F | 58.4 °F | 2.48 in. |
| November | 28.8 °F | 43.0 °F | 3.7 in. |
| December | 23.4 °F | 34.5 °F | 3.81 in. |
| Annual | 35.3 °F | 57.6 °F | 29.32 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |