Amherst, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 2.2 °C (low) to 18 °C (high). Annual precipitation averages 453.9 Millimeters. Amherst is located in USDA Plant Hardiness Zone 5b. 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 | -9.2 °C | 5.4 °C | 8.38 mm |
| February | -8.3 °C | 6.7 °C | 11.43 mm |
| March | -3.8 °C | 12.3 °C | 22.1 mm |
| April | 0.7 °C | 16.7 °C | 49.02 mm |
| May | 6.9 °C | 21.9 °C | 72.39 mm |
| June | 12.7 °C | 28.5 °C | 71.37 mm |
| July | 15.8 °C | 31.7 °C | 71.12 mm |
| August | 14.5 °C | 30.6 °C | 58.67 mm |
| September | 9.1 °C | 26.5 °C | 34.54 mm |
| October | 1.6 °C | 18.7 °C | 32.77 mm |
| November | -4.4 °C | 11.6 °C | 12.7 mm |
| December | -9.1 °C | 5.7 °C | 9.4 mm |
| Annual | 2.2 °C | 18 °C | 453.89 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 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |