Grayland, Washington has a Temperate Oceanic Climate climate (Köppen classification: Cfb). Average annual temperatures range from 7.1 °C (low) to 14.1 °C (high). Annual precipitation averages 1873 Millimeters. Grayland is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.8 °C | 9.2 °C | 284.48 mm |
| February | 3.5 °C | 10.3 °C | 179.58 mm |
| March | 4.3 °C | 11.4 °C | 215.14 mm |
| April | 5.5 °C | 13.1 °C | 152.15 mm |
| May | 7.9 °C | 15.2 °C | 88.39 mm |
| June | 9.9 °C | 16.9 °C | 61.72 mm |
| July | 11.7 °C | 18.6 °C | 29.46 mm |
| August | 11.7 °C | 19.4 °C | 41.4 mm |
| September | 10.4 °C | 19 °C | 69.85 mm |
| October | 7.6 °C | 15.6 °C | 188.98 mm |
| November | 5.3 °C | 11.6 °C | 286.51 mm |
| December | 3.5 °C | 8.9 °C | 275.34 mm |
| Annual | 7.1 °C | 14.1 °C | 1873 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfb - Temperate Oceanic Climate |