Herald, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 9.1 °C (low) to 23.5 °C (high). Annual precipitation averages 479.1 Millimeters. Herald 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. 21 - Dec. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.9 °C | 13.2 °C | 93.98 mm |
| February | 5.1 °C | 16.1 °C | 87.12 mm |
| March | 6.7 °C | 18.9 °C | 69.6 mm |
| April | 8.1 °C | 22 °C | 40.39 mm |
| May | 10.8 °C | 26.3 °C | 22.86 mm |
| June | 13.3 °C | 30.6 °C | 4.83 mm |
| July | 14.8 °C | 33.4 °C | 0.25 mm |
| August | 14.6 °C | 32.9 °C | 0.76 mm |
| September | 13.3 °C | 31.2 °C | 2.79 mm |
| October | 9.8 °C | 25.7 °C | 22.61 mm |
| November | 5.7 °C | 18.3 °C | 45.72 mm |
| December | 3.6 °C | 13.3 °C | 88.14 mm |
| Annual | 9.1 °C | 23.5 °C | 479.05 mm |
| Average First Frost Date | Dec. 21 - Dec. 31 |
| 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 | Csb - Warm-Summer Mediterranean Climate |