Kirkwood, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 31 °F (low) to 53.5 °F (high). Annual precipitation averages 55.9 Inches. Kirkwood is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Jun. 11 - Jun. 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.8 °F | 39.8 °F | 9.59 in. |
| February | 19.7 °F | 39.7 °F | 8.81 in. |
| March | 21.8 °F | 43.1 °F | 8.12 in. |
| April | 24.7 °F | 46.9 °F | 4.55 in. |
| May | 31.5 °F | 54.5 °F | 3.41 in. |
| June | 39.2 °F | 64.4 °F | 1.11 in. |
| July | 46.7 °F | 72.8 °F | 0.41 in. |
| August | 46.3 °F | 72.4 °F | 0.37 in. |
| September | 41.6 °F | 67.0 °F | 0.76 in. |
| October | 33.4 °F | 56.7 °F | 3.13 in. |
| November | 25.5 °F | 45.7 °F | 5.93 in. |
| December | 20.4 °F | 38.6 °F | 9.68 in. |
| Annual | 31 °F | 53.5 °F | 55.87 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | Jun. 11 - Jun. 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |