Norwalk, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 12.9 °C (low) to 24 °C (high). Annual precipitation averages 345.4 Millimeters. Norwalk is located in USDA Plant Hardiness Zone 10b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 8.2 °C | 19.9 °C | 83.82 mm |
| February | 8.9 °C | 19.8 °C | 93.47 mm |
| March | 10.4 °C | 20.6 °C | 51.56 mm |
| April | 11.6 °C | 22.6 °C | 17.02 mm |
| May | 13.9 °C | 23.7 °C | 6.86 mm |
| June | 15.9 °C | 25.7 °C | 1.78 mm |
| July | 17.7 °C | 28.5 °C | 1.02 mm |
| August | 18.1 °C | 29.5 °C | 0.25 mm |
| September | 17.2 °C | 29.1 °C | 3.3 mm |
| October | 14.6 °C | 26.6 °C | 13.21 mm |
| November | 10.7 °C | 22.8 °C | 18.03 mm |
| December | 7.9 °C | 19.7 °C | 55.12 mm |
| Annual | 12.9 °C | 24 °C | 345.44 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 | Csa - Hot-Summer Mediterranean Climate |