Dellwood, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.1 °C (low) to 12.6 °C (high). Annual precipitation averages 861.6 Millimeters. Dellwood is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.2 °C | -4.9 °C | 24.13 mm |
| February | -12.4 °C | -2.1 °C | 23.37 mm |
| March | -5.8 °C | 4.9 °C | 42.93 mm |
| April | 1.6 °C | 13 °C | 80.01 mm |
| May | 8.6 °C | 20.1 °C | 107.95 mm |
| June | 14.3 °C | 25.3 °C | 122.94 mm |
| July | 17.1 °C | 27.8 °C | 108.97 mm |
| August | 15.6 °C | 26.6 °C | 113.54 mm |
| September | 10.9 °C | 22.3 °C | 87.63 mm |
| October | 3.7 °C | 14.3 °C | 75.69 mm |
| November | -3.4 °C | 5.6 °C | 41.66 mm |
| December | -10.3 °C | -2 °C | 32.77 mm |
| Annual | 2.1 °C | 12.6 °C | 861.59 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |