Alturas, California has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from -0.2 °C (low) to 17.3 °C (high). Annual precipitation averages 299.7 Millimeters. 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 | -6.2 °C | 6.3 °C | 34.8 mm |
| February | -5.2 °C | 8.1 °C | 27.43 mm |
| March | -3.4 °C | 11.2 °C | 36.83 mm |
| April | -1.5 °C | 14.2 °C | 32.26 mm |
| May | 2.2 °C | 19.4 °C | 39.62 mm |
| June | 5.3 °C | 25.1 °C | 16 mm |
| July | 8.3 °C | 31.4 °C | 6.6 mm |
| August | 7.1 °C | 30.6 °C | 7.37 mm |
| September | 3.2 °C | 26.4 °C | 7.87 mm |
| October | -1.3 °C | 18.9 °C | 18.8 mm |
| November | -4.3 °C | 10.6 °C | 34.54 mm |
| December | -6.7 °C | 5.3 °C | 37.59 mm |
| Annual | -0.2 °C | 17.3 °C | 299.71 mm |
| 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 : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |