Greenbush, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -2.5 °C (low) to 9 °C (high). Annual precipitation averages 623.8 Millimeters. Greenbush is located in USDA Plant Hardiness Zone 3b. 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 | -20.7 °C | -10.2 °C | 18.29 mm |
| February | -19.3 °C | -7.6 °C | 15.49 mm |
| March | -11.3 °C | 0.1 °C | 20.57 mm |
| April | -2.3 °C | 9.5 °C | 27.69 mm |
| May | 4.8 °C | 17.5 °C | 80.01 mm |
| June | 11.2 °C | 22.8 °C | 117.86 mm |
| July | 13 °C | 25.4 °C | 94.74 mm |
| August | 11.4 °C | 25.1 °C | 78.23 mm |
| September | 6.6 °C | 20.1 °C | 67.82 mm |
| October | 0.2 °C | 11.2 °C | 51.05 mm |
| November | -7.8 °C | 1.2 °C | 27.94 mm |
| December | -15.9 °C | -6.8 °C | 24.13 mm |
| Annual | -2.5 °C | 9 °C | 623.82 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 3b : -37.2°C to -34.4°C |
| Plant Hardiness Zone - 2012 | Zone 3a : -40°C to -37.2°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |