Basalt, Colorado has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.4 °F (low) to 60.6 °F (high). Annual precipitation averages 16.8 Inches. Basalt 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 | 9.3 °F | 36.1 °F | 1.21 in. |
| February | 14.9 °F | 40.8 °F | 1.5 in. |
| March | 22.5 °F | 50.5 °F | 0.9 in. |
| April | 28.7 °F | 58.3 °F | 2.01 in. |
| May | 35.9 °F | 67.8 °F | 1.59 in. |
| June | 42.9 °F | 79.5 °F | 1.08 in. |
| July | 49.6 °F | 86.2 °F | 1.26 in. |
| August | 48.0 °F | 83.6 °F | 1.68 in. |
| September | 40.1 °F | 76.0 °F | 2.3 in. |
| October | 29.9 °F | 63.7 °F | 1.26 in. |
| November | 19.9 °F | 48.4 °F | 0.97 in. |
| December | 11.2 °F | 35.9 °F | 1.01 in. |
| Annual | 29.4 °F | 60.6 °F | 16.77 in. |
| 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 : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Exceptional Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |