Plummer, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.8 °C (low) to 9.6 °C (high). Annual precipitation averages 607.1 Millimeters. Plummer is located in USDA Plant Hardiness Zone 3b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -19.9 °C | -9.6 °C | 17.27 mm |
| February | -18.3 °C | -7 °C | 15.49 mm |
| March | -10.2 °C | 0.7 °C | 22.35 mm |
| April | -1.7 °C | 10.3 °C | 33.27 mm |
| May | 5.6 °C | 18.3 °C | 76.96 mm |
| June | 11.9 °C | 23.4 °C | 102.36 mm |
| July | 13.8 °C | 25.8 °C | 89.66 mm |
| August | 12.2 °C | 25.4 °C | 78.49 mm |
| September | 7.4 °C | 20.3 °C | 72.39 mm |
| October | 0.7 °C | 11.6 °C | 54.36 mm |
| November | -7.4 °C | 1.7 °C | 23.62 mm |
| December | -15.1 °C | -6.2 °C | 20.83 mm |
| Annual | -1.8 °C | 9.6 °C | 607.05 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 3b : -37.2°C to -34.4°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |