Johannesburg, California has a Hot Desert Climate climate (Köppen classification: BWh). Average annual temperatures range from 11.2 °C (low) to 23.8 °C (high). Annual precipitation averages 165.4 Millimeters. Johannesburg is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.6 °C | 13 °C | 38.86 mm |
| February | 4.2 °C | 14.5 °C | 42.67 mm |
| March | 6.3 °C | 18.2 °C | 21.34 mm |
| April | 8.3 °C | 21.8 °C | 8.38 mm |
| May | 12.5 °C | 27 °C | 2.79 mm |
| June | 17.4 °C | 32.6 °C | 0.76 mm |
| July | 20.8 °C | 36.1 °C | 4.06 mm |
| August | 20.6 °C | 35.7 °C | 2.29 mm |
| September | 17.6 °C | 31.7 °C | 5.33 mm |
| October | 12.4 °C | 24.9 °C | 8.64 mm |
| November | 7 °C | 17.7 °C | 10.67 mm |
| December | 3.2 °C | 12.4 °C | 19.56 mm |
| Annual | 11.2 °C | 23.8 °C | 165.35 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BWh - Hot Desert Climate |