San Luis, Colorado has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 26.9 °F (low) to 58.7 °F (high). Annual precipitation averages 10.5 Inches. San Luis is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.2 °F | 35.8 °F | 0.3 in. |
| February | 11.4 °F | 40.0 °F | 0.41 in. |
| March | 20.3 °F | 49.9 °F | 0.56 in. |
| April | 26.4 °F | 57.6 °F | 1.04 in. |
| May | 34.4 °F | 66.7 °F | 0.94 in. |
| June | 42.1 °F | 77.7 °F | 0.7 in. |
| July | 47.3 °F | 80.5 °F | 1.86 in. |
| August | 46.0 °F | 78.5 °F | 1.6 in. |
| September | 38.5 °F | 72.5 °F | 1.22 in. |
| October | 27.2 °F | 61.4 °F | 0.82 in. |
| November | 16.6 °F | 47.8 °F | 0.57 in. |
| December | 6.8 °F | 36.4 °F | 0.52 in. |
| Annual | 26.9 °F | 58.7 °F | 10.54 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |