Sedan, Kansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8 °C (low) to 20.8 °C (high). Annual precipitation averages 1039.6 Millimeters. Sedan is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.1 °C | 7.4 °C | 34.29 mm |
| February | -3.2 °C | 10.1 °C | 43.69 mm |
| March | 1.9 °C | 15.6 °C | 72.64 mm |
| April | 7.6 °C | 20.7 °C | 109.98 mm |
| May | 13.4 °C | 25.1 °C | 152.4 mm |
| June | 18.6 °C | 29.9 °C | 144.53 mm |
| July | 21 °C | 32.9 °C | 101.6 mm |
| August | 19.9 °C | 32.7 °C | 92.46 mm |
| September | 15.2 °C | 28.4 °C | 89.41 mm |
| October | 8.3 °C | 22.2 °C | 97.79 mm |
| November | 2 °C | 15.2 °C | 54.61 mm |
| December | -3.3 °C | 8.9 °C | 46.23 mm |
| Annual | 8 °C | 20.8 °C | 1039.63 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |