Greenfield, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.4 °F (low) to 53.9 °F (high). Annual precipitation averages 31.5 Inches. Greenfield is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.1 °F | 22.2 °F | 0.77 in. |
| February | 8.3 °F | 27.0 °F | 0.88 in. |
| March | 20.9 °F | 39.6 °F | 1.48 in. |
| April | 34.4 °F | 54.5 °F | 2.83 in. |
| May | 47.4 °F | 67.6 °F | 4.24 in. |
| June | 58.1 °F | 77.1 °F | 4.71 in. |
| July | 62.3 °F | 81.8 °F | 3.91 in. |
| August | 59.9 °F | 79.4 °F | 4.12 in. |
| September | 51.4 °F | 72.0 °F | 3.36 in. |
| October | 38.5 °F | 57.4 °F | 2.52 in. |
| November | 25.6 °F | 41.4 °F | 1.45 in. |
| December | 12.3 °F | 27.3 °F | 1.18 in. |
| Annual | 35.4 °F | 53.9 °F | 31.45 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |