Larkspur, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.6 °C (low) to 16.6 °C (high). Annual precipitation averages 516.9 Millimeters. Larkspur is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.9 °C | 6.3 °C | 18.03 mm |
| February | -8.2 °C | 6.7 °C | 19.3 mm |
| March | -4.6 °C | 11 °C | 45.21 mm |
| April | -1.2 °C | 14.3 °C | 62.99 mm |
| May | 3.8 °C | 19.4 °C | 67.31 mm |
| June | 8.8 °C | 25.9 °C | 50.8 mm |
| July | 12.2 °C | 29 °C | 65.79 mm |
| August | 11.4 °C | 27.8 °C | 68.58 mm |
| September | 6.9 °C | 24.1 °C | 43.94 mm |
| October | 0.6 °C | 17.4 °C | 31.24 mm |
| November | -4.8 °C | 10.8 °C | 23.62 mm |
| December | -8.9 °C | 6.2 °C | 20.07 mm |
| Annual | 0.6 °C | 16.6 °C | 516.88 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| 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 | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |