Ridgefield, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.3 °C (low) to 17.1 °C (high). Annual precipitation averages 1116.9 Millimeters. Ridgefield is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.5 °C | 8.1 °C | 161.04 mm |
| February | 1.4 °C | 10.3 °C | 117.35 mm |
| March | 3.1 °C | 13.1 °C | 123.95 mm |
| April | 4.8 °C | 15.9 °C | 93.73 mm |
| May | 8 °C | 19.9 °C | 67.31 mm |
| June | 10.3 °C | 22.6 °C | 46.74 mm |
| July | 12.6 °C | 26.8 °C | 11.43 mm |
| August | 12.5 °C | 27.5 °C | 17.02 mm |
| September | 10 °C | 24.3 °C | 44.2 mm |
| October | 6.4 °C | 17.4 °C | 100.08 mm |
| November | 3.5 °C | 11.4 °C | 163.07 mm |
| December | 1.4 °C | 7.6 °C | 170.94 mm |
| Annual | 6.3 °C | 17.1 °C | 1116.86 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |