Del Rio, California has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 9.3 °C (low) to 23.4 °C (high). Annual precipitation averages 333.3 Millimeters. 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 | 3.6 °C | 12.8 °C | 74.68 mm |
| February | 4.9 °C | 16 °C | 53.09 mm |
| March | 6.4 °C | 19 °C | 55.12 mm |
| April | 8.1 °C | 21.8 °C | 26.67 mm |
| May | 11 °C | 26.4 °C | 14.99 mm |
| June | 13.6 °C | 30.7 °C | 2.29 mm |
| July | 15.6 °C | 33.5 °C | 0 mm |
| August | 15.1 °C | 32.8 °C | 0.51 mm |
| September | 13.6 °C | 30.7 °C | 2.79 mm |
| October | 10 °C | 25.5 °C | 16 mm |
| November | 5.8 °C | 18.3 °C | 32.51 mm |
| December | 3.4 °C | 13.1 °C | 54.61 mm |
| Annual | 9.3 °C | 23.4 °C | 333.26 mm |
| 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 : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |