Sebastopol, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 44.1 °F (low) to 70.7 °F (high). Annual precipitation averages 37.5 Inches. Sebastopol is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 37.8 °F | 57.5 °F | 6.92 in. |
| February | 39.1 °F | 61.1 °F | 7.33 in. |
| March | 40.9 °F | 64.1 °F | 4.99 in. |
| April | 42.5 °F | 68.2 °F | 2.35 in. |
| May | 45.9 °F | 73.3 °F | 1.39 in. |
| June | 49.3 °F | 79.3 °F | 0.33 in. |
| July | 51.2 °F | 81.3 °F | 0.03 in. |
| August | 51.3 °F | 82.0 °F | 0.13 in. |
| September | 49.0 °F | 82.1 °F | 0.16 in. |
| October | 45.2 °F | 76.7 °F | 1.8 in. |
| November | 40.3 °F | 65.4 °F | 3.87 in. |
| December | 37.0 °F | 57.5 °F | 8.21 in. |
| Annual | 44.1 °F | 70.7 °F | 37.51 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 30-40 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 | Csb - Warm-Summer Mediterranean Climate |