Walnut Park, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 13.2 °C (low) to 23.6 °C (high). Annual precipitation averages 359.4 Millimeters. Walnut Park is located in USDA Plant Hardiness Zone 10b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 8.8 °C | 19.7 °C | 83.31 mm |
| February | 9.5 °C | 19.7 °C | 91.95 mm |
| March | 10.7 °C | 20.3 °C | 58.93 mm |
| April | 11.9 °C | 22.2 °C | 18.54 mm |
| May | 14 °C | 23.2 °C | 7.37 mm |
| June | 15.9 °C | 24.9 °C | 1.78 mm |
| July | 17.7 °C | 27.7 °C | 1.02 mm |
| August | 18.1 °C | 28.7 °C | 0.51 mm |
| September | 17.3 °C | 28.2 °C | 3.05 mm |
| October | 14.9 °C | 25.9 °C | 13.72 mm |
| November | 11.3 °C | 22.6 °C | 19.56 mm |
| December | 8.6 °C | 19.5 °C | 59.69 mm |
| Annual | 13.2 °C | 23.6 °C | 359.43 mm |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Free |
| Plant Hardiness Zone | Zone 10b : 1.7°C to 4.4°C |
| Plant Hardiness Zone - 2012 | Zone 10b : 1.7°C to 4.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |