Cottage Lake, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 43.7 °F (low) to 60.3 °F (high). Annual precipitation averages 46.8 Inches. Cottage Lake is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.4 °F | 46.7 °F | 6.26 in. |
| February | 35.4 °F | 49.5 °F | 4.5 in. |
| March | 37.8 °F | 53.5 °F | 4.64 in. |
| April | 41.2 °F | 58.5 °F | 4.07 in. |
| May | 46.6 °F | 65.2 °F | 2.9 in. |
| June | 50.8 °F | 69.5 °F | 2.56 in. |
| July | 54.3 °F | 76.2 °F | 1.05 in. |
| August | 54.4 °F | 76.8 °F | 1.03 in. |
| September | 50.5 °F | 70.8 °F | 2.26 in. |
| October | 44.3 °F | 60.1 °F | 4.35 in. |
| November | 38.8 °F | 51.2 °F | 6.96 in. |
| December | 35.1 °F | 45.7 °F | 6.18 in. |
| Annual | 43.7 °F | 60.3 °F | 46.76 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 40-50 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 |