Covington, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.4 °C (low) to 15.8 °C (high). Annual precipitation averages 1217.7 Millimeters. Covington 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 | 1.8 °C | 8.1 °C | 162.05 mm |
| February | 1.8 °C | 9.6 °C | 113.79 mm |
| March | 3 °C | 11.8 °C | 134.11 mm |
| April | 4.8 °C | 14.7 °C | 107.7 mm |
| May | 7.9 °C | 18.6 °C | 68.58 mm |
| June | 10.3 °C | 21.1 °C | 61.21 mm |
| July | 12.3 °C | 24.7 °C | 25.65 mm |
| August | 12.4 °C | 24.9 °C | 33.78 mm |
| September | 10.2 °C | 21.7 °C | 54.36 mm |
| October | 6.7 °C | 15.6 °C | 123.44 mm |
| November | 3.7 °C | 10.7 °C | 172.97 mm |
| December | 1.5 °C | 7.6 °C | 160.02 mm |
| Annual | 6.4 °C | 15.8 °C | 1217.66 mm |
| 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 : -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 |