Plummer, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 1.9 °C (low) to 14.2 °C (high). Annual precipitation averages 744.7 Millimeters. 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 | -4.3 °C | 2.2 °C | 96.01 mm |
| February | -4 °C | 4.3 °C | 75.18 mm |
| March | -1.8 °C | 8.7 °C | 81.79 mm |
| April | 0.8 °C | 13.2 °C | 62.48 mm |
| May | 4.4 °C | 18.6 °C | 62.23 mm |
| June | 7.4 °C | 21.8 °C | 49.28 mm |
| July | 9.8 °C | 28.1 °C | 19.56 mm |
| August | 9.5 °C | 28.6 °C | 19.3 mm |
| September | 5.6 °C | 23 °C | 25.15 mm |
| October | 1.4 °C | 14.7 °C | 62.99 mm |
| November | -1.8 °C | 6.1 °C | 93.98 mm |
| December | -4.8 °C | 1.4 °C | 96.77 mm |
| Annual | 1.9 °C | 14.2 °C | 744.72 mm |
| 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 : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |