San Jacinto, California has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 49 °F (low) to 80.3 °F (high). Annual precipitation averages 12.3 Inches. San Jacinto is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Feb. 11 - Feb. 20 through the first frost around Dec. 1 - Dec. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 39.2 °F | 66.8 °F | 2.61 in. |
| February | 40.0 °F | 66.7 °F | 2.92 in. |
| March | 42.8 °F | 70.5 °F | 1.88 in. |
| April | 45.7 °F | 75.7 °F | 0.78 in. |
| May | 51.1 °F | 81.9 °F | 0.4 in. |
| June | 55.0 °F | 89.8 °F | 0.05 in. |
| July | 60.9 °F | 96.8 °F | 0.17 in. |
| August | 61.6 °F | 98.0 °F | 0.11 in. |
| September | 58.3 °F | 93.5 °F | 0.24 in. |
| October | 51.0 °F | 83.8 °F | 0.62 in. |
| November | 43.9 °F | 74.0 °F | 0.77 in. |
| December | 38.0 °F | 66.0 °F | 1.77 in. |
| Annual | 49 °F | 80.3 °F | 12.32 in. |
| Average First Frost Date | Dec. 1 - Dec. 10 |
| Average Last Frost Date | Feb. 11 - Feb. 20 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9b : 25°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |