Alturas, California has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 31.6 °F (low) to 63.1 °F (high). Annual precipitation averages 11.8 Inches. Alturas is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.8 °F | 43.3 °F | 1.37 in. |
| February | 22.6 °F | 46.6 °F | 1.08 in. |
| March | 25.8 °F | 52.2 °F | 1.45 in. |
| April | 29.3 °F | 57.5 °F | 1.27 in. |
| May | 36.0 °F | 67.0 °F | 1.56 in. |
| June | 41.5 °F | 77.2 °F | 0.63 in. |
| July | 46.9 °F | 88.6 °F | 0.26 in. |
| August | 44.8 °F | 87.0 °F | 0.29 in. |
| September | 37.8 °F | 79.5 °F | 0.31 in. |
| October | 29.7 °F | 66.0 °F | 0.74 in. |
| November | 24.2 °F | 51.1 °F | 1.36 in. |
| December | 20.0 °F | 41.6 °F | 1.48 in. |
| Annual | 31.6 °F | 63.1 °F | 11.8 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |