Bremerton, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 7 °C (low) to 15.8 °C (high). Annual precipitation averages 1207 Millimeters. Bremerton is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.4 °C | 8.5 °C | 192.02 mm |
| February | 2.4 °C | 9.9 °C | 113.79 mm |
| March | 3.7 °C | 12.2 °C | 131.32 mm |
| April | 5.4 °C | 15 °C | 80.52 mm |
| May | 8.4 °C | 18.4 °C | 53.09 mm |
| June | 10.8 °C | 20.6 °C | 38.35 mm |
| July | 12.7 °C | 24.2 °C | 19.56 mm |
| August | 12.8 °C | 24.7 °C | 25.4 mm |
| September | 10.8 °C | 21.6 °C | 45.47 mm |
| October | 7.4 °C | 15.7 °C | 113.03 mm |
| November | 4.3 °C | 10.9 °C | 189.48 mm |
| December | 2.3 °C | 8 °C | 204.98 mm |
| Annual | 7 °C | 15.8 °C | 1207.01 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |