Vallecito, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 7.9 °C (low) to 23.2 °C (high). Annual precipitation averages 875.3 Millimeters. Vallecito is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.2 °C | 13.3 °C | 173.23 mm |
| February | 2.7 °C | 14.7 °C | 146.3 mm |
| March | 4.2 °C | 17.4 °C | 131.57 mm |
| April | 5.6 °C | 19.9 °C | 77.72 mm |
| May | 8.6 °C | 24.9 °C | 44.45 mm |
| June | 12.1 °C | 30.6 °C | 12.19 mm |
| July | 15.8 °C | 35.1 °C | 2.03 mm |
| August | 15.4 °C | 34.7 °C | 5.08 mm |
| September | 13.1 °C | 31.6 °C | 5.84 mm |
| October | 8.9 °C | 25.3 °C | 42.93 mm |
| November | 4.4 °C | 17.9 °C | 82.55 mm |
| December | 2 °C | 12.8 °C | 151.38 mm |
| Annual | 7.9 °C | 23.2 °C | 875.27 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 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 | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |