Lake Cavanaugh, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5 °C (low) to 13.9 °C (high). Annual precipitation averages 1760.7 Millimeters. Lake Cavanaugh is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.1 °C | 5.3 °C | 216.92 mm |
| February | 0.3 °C | 6.8 °C | 171.2 mm |
| March | 1.2 °C | 9.3 °C | 186.69 mm |
| April | 3.2 °C | 13.1 °C | 99.06 mm |
| May | 6.4 °C | 17.5 °C | 86.11 mm |
| June | 8.7 °C | 19.9 °C | 89.15 mm |
| July | 11.3 °C | 23.7 °C | 45.47 mm |
| August | 11.9 °C | 24.3 °C | 41.15 mm |
| September | 8.9 °C | 20.4 °C | 92.2 mm |
| October | 5.5 °C | 13.1 °C | 195.07 mm |
| November | 2.2 °C | 7.8 °C | 284.23 mm |
| December | 0.2 °C | 5.2 °C | 253.49 mm |
| Annual | 5 °C | 13.9 °C | 1760.74 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 50-75 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 |