Sedan, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.6 °C (low) to 11.5 °C (high). Annual precipitation averages 697.5 Millimeters. Sedan 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 | -16.5 °C | -6.8 °C | 16.76 mm |
| February | -14.8 °C | -4.2 °C | 16.76 mm |
| March | -7.6 °C | 2.7 °C | 33.02 mm |
| April | 0.2 °C | 12.2 °C | 59.69 mm |
| May | 7.4 °C | 19.3 °C | 79.25 mm |
| June | 13.4 °C | 24.8 °C | 109.98 mm |
| July | 16.1 °C | 27.6 °C | 104.39 mm |
| August | 14.3 °C | 26.3 °C | 93.47 mm |
| September | 9.6 °C | 22 °C | 68.83 mm |
| October | 2.2 °C | 13.5 °C | 65.79 mm |
| November | -5.2 °C | 3.9 °C | 29.21 mm |
| December | -12.4 °C | -3.7 °C | 20.32 mm |
| Annual | 0.6 °C | 11.5 °C | 697.47 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 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |