Bothell, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 44.6 °F (low) to 60.9 °F (high). Annual precipitation averages 41.4 Inches. 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 | 36.2 °F | 47.3 °F | 5.61 in. |
| February | 36.3 °F | 50.0 °F | 3.95 in. |
| March | 38.7 °F | 53.9 °F | 4.33 in. |
| April | 42.1 °F | 59.1 °F | 3.38 in. |
| May | 47.3 °F | 65.9 °F | 2.27 in. |
| June | 51.7 °F | 70.1 °F | 2.0 in. |
| July | 55.0 °F | 76.4 °F | 0.91 in. |
| August | 55.2 °F | 77.2 °F | 1.11 in. |
| September | 51.5 °F | 71.5 °F | 1.8 in. |
| October | 45.4 °F | 60.7 °F | 3.91 in. |
| November | 39.8 °F | 51.8 °F | 6.25 in. |
| December | 36.0 °F | 46.4 °F | 5.9 in. |
| Annual | 44.6 °F | 60.9 °F | 41.42 in. |
| 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 : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |