Del Rio, California has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 48.7 °F (low) to 74.1 °F (high). Annual precipitation averages 13.1 Inches. Del Rio is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Jan. 21 - Jan. 31 through the first frost around Dec. 11 - Dec. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 38.5 °F | 55.0 °F | 2.94 in. |
| February | 40.9 °F | 60.8 °F | 2.09 in. |
| March | 43.6 °F | 66.2 °F | 2.17 in. |
| April | 46.5 °F | 71.3 °F | 1.05 in. |
| May | 51.8 °F | 79.6 °F | 0.59 in. |
| June | 56.5 °F | 87.2 °F | 0.09 in. |
| July | 60.0 °F | 92.3 °F | 0.0 in. |
| August | 59.2 °F | 91.0 °F | 0.02 in. |
| September | 56.4 °F | 87.2 °F | 0.11 in. |
| October | 50.0 °F | 77.9 °F | 0.63 in. |
| November | 42.4 °F | 65.0 °F | 1.28 in. |
| December | 38.1 °F | 55.6 °F | 2.15 in. |
| Annual | 48.7 °F | 74.1 °F | 13.12 in. |
| Average First Frost Date | Dec. 11 - Dec. 20 |
| Average Last Frost Date | Jan. 21 - Jan. 31 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9b : 25°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |