Lake Forest Park, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 44.6 °F (low) to 60.6 °F (high). Annual precipitation averages 39.7 Inches. Lake Forest Park is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 36.1 °F | 47.2 °F | 5.59 in. |
| February | 36.1 °F | 49.9 °F | 3.7 in. |
| March | 38.6 °F | 53.9 °F | 4.15 in. |
| April | 42.0 °F | 58.7 °F | 3.2 in. |
| May | 47.3 °F | 65.6 °F | 2.11 in. |
| June | 51.6 °F | 69.8 °F | 1.89 in. |
| July | 55.2 °F | 76.0 °F | 0.9 in. |
| August | 55.3 °F | 76.6 °F | 1.16 in. |
| September | 51.6 °F | 71.0 °F | 1.69 in. |
| October | 45.4 °F | 60.4 °F | 3.76 in. |
| November | 39.7 °F | 51.7 °F | 5.87 in. |
| December | 35.8 °F | 46.3 °F | 5.67 in. |
| Annual | 44.6 °F | 60.6 °F | 39.69 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 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 | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |