Colby, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.2 °C (low) to 18.9 °C (high). Annual precipitation averages 524.5 Millimeters. Colby is located in USDA Plant Hardiness Zone 6a. 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 | -8.8 °C | 5.9 °C | 9.65 mm |
| February | -7.6 °C | 7.6 °C | 13.21 mm |
| March | -3.2 °C | 13.3 °C | 24.13 mm |
| April | 1.6 °C | 17.9 °C | 46.23 mm |
| May | 7.9 °C | 23.3 °C | 78.23 mm |
| June | 13.9 °C | 29.8 °C | 65.02 mm |
| July | 16.9 °C | 32.6 °C | 98.55 mm |
| August | 15.7 °C | 31.1 °C | 81.53 mm |
| September | 10.6 °C | 27.1 °C | 38.86 mm |
| October | 3.1 °C | 19.8 °C | 36.83 mm |
| November | -3.5 °C | 12.2 °C | 17.53 mm |
| December | -8.1 °C | 6.4 °C | 14.73 mm |
| Annual | 3.2 °C | 18.9 °C | 524.5 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 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |