Gustine, California has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 9 °C (low) to 24.3 °C (high). Annual precipitation averages 299 Millimeters. Gustine is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.2 °C | 13.2 °C | 70.1 mm |
| February | 4.6 °C | 16.5 °C | 59.44 mm |
| March | 6.3 °C | 19.6 °C | 44.96 mm |
| April | 7.7 °C | 23.1 °C | 17.53 mm |
| May | 10.7 °C | 27.8 °C | 11.68 mm |
| June | 13.6 °C | 31.9 °C | 1.27 mm |
| July | 15.7 °C | 34.9 °C | 0 mm |
| August | 15.1 °C | 34.2 °C | 0 mm |
| September | 13.4 °C | 31.9 °C | 1.02 mm |
| October | 9.8 °C | 26.6 °C | 14.22 mm |
| November | 5.4 °C | 18.8 °C | 26.16 mm |
| December | 2.7 °C | 13.4 °C | 52.58 mm |
| Annual | 9 °C | 24.3 °C | 298.96 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 20-30 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 | BSk - Cold Semi-Arid Climate |