Underwood, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Annual precipitation averages 660.4 Millimeters. Underwood is located in USDA Plant Hardiness Zone 4a. 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 | -17.7 °C | -7.6 °C | 17.02 mm |
| February | -15.9 °C | -4.9 °C | 16 mm |
| March | -8.3 °C | 2.3 °C | 27.69 mm |
| April | -0.4 °C | 11.3 °C | 50.8 mm |
| May | 7.1 °C | 18.8 °C | 84.58 mm |
| June | 13.1 °C | 24.1 °C | 109.47 mm |
| July | 15.6 °C | 26.6 °C | 96.27 mm |
| August | 14.2 °C | 25.7 °C | 79.76 mm |
| September | 9.4 °C | 21.4 °C | 72.64 mm |
| October | 2 °C | 12.8 °C | 63.5 mm |
| November | -5.7 °C | 3.2 °C | 23.37 mm |
| December | -13.3 °C | -4.4 °C | 19.3 mm |
| Annual | 0 °C | 10.8 °C | 660.4 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |