Bainbridge Island, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 45.2 °F (low) to 60.6 °F (high). Annual precipitation averages 41.1 Inches. Bainbridge Island 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. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 37.3 °F | 47.3 °F | 6.4 in. |
| February | 37.3 °F | 49.8 °F | 3.75 in. |
| March | 39.4 °F | 53.8 °F | 4.46 in. |
| April | 42.5 °F | 59.0 °F | 2.79 in. |
| May | 47.4 °F | 65.4 °F | 1.93 in. |
| June | 51.6 °F | 69.7 °F | 1.65 in. |
| July | 55.0 °F | 75.9 °F | 0.83 in. |
| August | 55.3 °F | 76.7 °F | 1.0 in. |
| September | 52.0 °F | 71.2 °F | 1.62 in. |
| October | 46.5 °F | 60.4 °F | 4.02 in. |
| November | 40.7 °F | 51.7 °F | 6.16 in. |
| December | 37.1 °F | 46.5 °F | 6.44 in. |
| Annual | 45.2 °F | 60.6 °F | 41.05 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 9a : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |