Gustine, California has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 48.2 °F (low) to 75.8 °F (high). Annual precipitation averages 11.8 Inches. 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 | 37.7 °F | 55.7 °F | 2.76 in. |
| February | 40.3 °F | 61.7 °F | 2.34 in. |
| March | 43.3 °F | 67.2 °F | 1.77 in. |
| April | 45.9 °F | 73.6 °F | 0.69 in. |
| May | 51.3 °F | 82.0 °F | 0.46 in. |
| June | 56.4 °F | 89.5 °F | 0.05 in. |
| July | 60.2 °F | 94.9 °F | 0.0 in. |
| August | 59.2 °F | 93.5 °F | 0.0 in. |
| September | 56.2 °F | 89.5 °F | 0.04 in. |
| October | 49.7 °F | 79.8 °F | 0.56 in. |
| November | 41.7 °F | 65.9 °F | 1.03 in. |
| December | 36.8 °F | 56.1 °F | 2.07 in. |
| Annual | 48.2 °F | 75.8 °F | 11.77 in. |
| 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 : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 9a : 20°F to 25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |