Gardner, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.4 °C (low) to 16.9 °C (high). Annual precipitation averages 341.9 Millimeters. Gardner 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 | -9.3 °C | 5.8 °C | 12.95 mm |
| February | -8.2 °C | 7.2 °C | 12.7 mm |
| March | -4.4 °C | 11.8 °C | 26.16 mm |
| April | -1 °C | 15.1 °C | 35.05 mm |
| May | 3.8 °C | 20.5 °C | 35.05 mm |
| June | 8.6 °C | 26.8 °C | 25.15 mm |
| July | 11.7 °C | 28.9 °C | 61.47 mm |
| August | 10.6 °C | 27.6 °C | 54.36 mm |
| September | 6.5 °C | 24.2 °C | 21.34 mm |
| October | 0.4 °C | 18 °C | 25.91 mm |
| November | -4.8 °C | 11.3 °C | 18.03 mm |
| December | -9.3 °C | 5.7 °C | 13.72 mm |
| Annual | 0.4 °C | 16.9 °C | 341.89 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 | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |