National City, California has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 13.3 °C (low) to 21.4 °C (high). Annual precipitation averages 244.3 Millimeters. National City is located in USDA Plant Hardiness Zone 10b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 8.8 °C | 19.1 °C | 44.7 mm |
| February | 9.3 °C | 18.8 °C | 59.44 mm |
| March | 10.7 °C | 19.1 °C | 39.12 mm |
| April | 12.1 °C | 20.1 °C | 18.03 mm |
| May | 14.3 °C | 20.8 °C | 5.84 mm |
| June | 15.9 °C | 21.7 °C | 1.27 mm |
| July | 17.8 °C | 23.5 °C | 1.52 mm |
| August | 18.4 °C | 24.7 °C | 0.51 mm |
| September | 17.6 °C | 24.8 °C | 2.54 mm |
| October | 14.6 °C | 23.5 °C | 9.65 mm |
| November | 11.2 °C | 21.7 °C | 19.05 mm |
| December | 8.3 °C | 18.8 °C | 42.67 mm |
| Annual | 13.3 °C | 21.4 °C | 244.34 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 | BSk - Cold Semi-Arid Climate |