Lafayette, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 2.4 °C (low) to 18.5 °C (high). Annual precipitation averages 397.3 Millimeters. Lafayette 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 | -7.8 °C | 7.5 °C | 13.21 mm |
| February | -6.9 °C | 8.1 °C | 14.48 mm |
| March | -2.6 °C | 13.4 °C | 37.34 mm |
| April | 1 °C | 16.6 °C | 50.8 mm |
| May | 6.1 °C | 21.4 °C | 62.99 mm |
| June | 11.1 °C | 28.3 °C | 41.4 mm |
| July | 14.6 °C | 31.7 °C | 42.93 mm |
| August | 13.3 °C | 30.6 °C | 35.81 mm |
| September | 8.7 °C | 26.1 °C | 33.02 mm |
| October | 2.1 °C | 18.8 °C | 29.72 mm |
| November | -3.4 °C | 12.1 °C | 22.35 mm |
| December | -7.9 °C | 7.1 °C | 13.21 mm |
| Annual | 2.4 °C | 18.5 °C | 397.26 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 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 | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |