Bothell, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 7 °C (low) to 16 °C (high). Annual precipitation averages 1052.1 Millimeters. Bothell is located in USDA Plant Hardiness Zone 8b. 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 | 2.3 °C | 8.5 °C | 142.49 mm |
| February | 2.4 °C | 10 °C | 100.33 mm |
| March | 3.7 °C | 12.2 °C | 109.98 mm |
| April | 5.6 °C | 15.1 °C | 85.85 mm |
| May | 8.5 °C | 18.8 °C | 57.66 mm |
| June | 10.9 °C | 21.2 °C | 50.8 mm |
| July | 12.8 °C | 24.7 °C | 23.11 mm |
| August | 12.9 °C | 25.1 °C | 28.19 mm |
| September | 10.8 °C | 21.9 °C | 45.72 mm |
| October | 7.4 °C | 15.9 °C | 99.31 mm |
| November | 4.3 °C | 11 °C | 158.75 mm |
| December | 2.2 °C | 8 °C | 149.86 mm |
| Annual | 7 °C | 16 °C | 1052.05 mm |
| 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 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |