Tomales, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 46.2 °F (low) to 65.3 °F (high). Annual precipitation averages 35.5 Inches. Tomales is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Jan. 21 - Jan. 31 through the first frost around Jan. 1 - Jan. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 40.8 °F | 56.9 °F | 6.81 in. |
| February | 42.5 °F | 58.5 °F | 7.03 in. |
| March | 43.2 °F | 60.2 °F | 4.74 in. |
| April | 44.2 °F | 62.8 °F | 2.34 in. |
| May | 46.9 °F | 66.4 °F | 1.32 in. |
| June | 49.4 °F | 70.3 °F | 0.35 in. |
| July | 51.2 °F | 72.0 °F | 0.04 in. |
| August | 51.8 °F | 73.3 °F | 0.11 in. |
| September | 50.5 °F | 73.0 °F | 0.15 in. |
| October | 48.0 °F | 70.3 °F | 1.67 in. |
| November | 44.6 °F | 63.1 °F | 3.77 in. |
| December | 41.2 °F | 56.4 °F | 7.18 in. |
| Annual | 46.2 °F | 65.3 °F | 35.51 in. |
| Average First Frost Date | Jan. 1 - Jan. 10 |
| Average Last Frost Date | Jan. 21 - Jan. 31 |
| 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 | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |