Derby, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.7 °C (low) to 19.9 °C (high). Annual precipitation averages 938.8 Millimeters. Derby is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.4 °C | 6.2 °C | 22.35 mm |
| February | -3.7 °C | 8.8 °C | 35.56 mm |
| March | 1.4 °C | 14.6 °C | 65.53 mm |
| April | 6.7 °C | 19.6 °C | 85.34 mm |
| May | 12.9 °C | 24.6 °C | 149.86 mm |
| June | 18.6 °C | 30.3 °C | 139.7 mm |
| July | 20.8 °C | 32.8 °C | 103.12 mm |
| August | 19.8 °C | 32 °C | 110.24 mm |
| September | 15.2 °C | 27.9 °C | 73.41 mm |
| October | 8.2 °C | 21.4 °C | 79.76 mm |
| November | 1.4 °C | 13.8 °C | 40.64 mm |
| December | -3.9 °C | 7.3 °C | 33.27 mm |
| Annual | 7.7 °C | 19.9 °C | 938.78 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 75-100 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |