Dexter, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.5 °C (low) to 11.7 °C (high). Annual precipitation averages 902.7 Millimeters. Dexter 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 | -14.4 °C | -5.8 °C | 25.65 mm |
| February | -12.3 °C | -3.3 °C | 24.89 mm |
| March | -5.9 °C | 3.6 °C | 45.47 mm |
| April | 1.1 °C | 12 °C | 92.2 mm |
| May | 8.1 °C | 19.1 °C | 119.63 mm |
| June | 14.1 °C | 24.7 °C | 138.68 mm |
| July | 15.7 °C | 26.4 °C | 113.28 mm |
| August | 14.3 °C | 25.2 °C | 107.95 mm |
| September | 9.7 °C | 21.8 °C | 96.01 mm |
| October | 2.7 °C | 14 °C | 66.8 mm |
| November | -4.1 °C | 5.1 °C | 38.86 mm |
| December | -10.7 °C | -2.6 °C | 33.27 mm |
| Annual | 1.5 °C | 11.7 °C | 902.69 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 4b : -31.7°C to -28.9°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 |