San Joaquin, California has a Cold Desert Climate climate (Köppen classification: BWk). Average annual temperatures range from 48.4 °F (low) to 76.3 °F (high). Annual precipitation averages 8.6 Inches. San Joaquin 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 | 37.4 °F | 55.5 °F | 1.68 in. |
| February | 39.8 °F | 61.7 °F | 1.56 in. |
| March | 42.4 °F | 68.1 °F | 1.46 in. |
| April | 45.8 °F | 74.2 °F | 0.83 in. |
| May | 52.0 °F | 82.9 °F | 0.38 in. |
| June | 56.9 °F | 90.4 °F | 0.09 in. |
| July | 62.3 °F | 95.4 °F | 0.0 in. |
| August | 61.2 °F | 94.8 °F | 0.01 in. |
| September | 57.1 °F | 90.4 °F | 0.12 in. |
| October | 49.4 °F | 80.0 °F | 0.45 in. |
| November | 40.6 °F | 66.1 °F | 0.64 in. |
| December | 35.8 °F | 55.9 °F | 1.41 in. |
| Annual | 48.4 °F | 76.3 °F | 8.63 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 | BWk - Cold Desert Climate |