Alamosa, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 24.6 °F (low) to 59.5 °F (high). Annual precipitation averages 7.7 Inches. Alamosa is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.1 °F | 34.2 °F | 0.42 in. |
| February | 7.3 °F | 40.5 °F | 0.24 in. |
| March | 17.3 °F | 51.6 °F | 0.55 in. |
| April | 24.4 °F | 59.2 °F | 0.62 in. |
| May | 34.0 °F | 68.3 °F | 0.69 in. |
| June | 41.3 °F | 78.4 °F | 0.47 in. |
| July | 47.2 °F | 81.5 °F | 1.25 in. |
| August | 45.1 °F | 79.4 °F | 1.12 in. |
| September | 37.5 °F | 73.8 °F | 1.0 in. |
| October | 25.4 °F | 62.8 °F | 0.66 in. |
| November | 13.0 °F | 48.8 °F | 0.4 in. |
| December | 2.0 °F | 35.7 °F | 0.3 in. |
| Annual | 24.6 °F | 59.5 °F | 7.72 in. |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |