Neilton, Washington has a Temperate Oceanic Climate climate (Köppen classification: Cfb). Average annual temperatures range from 5.6 °C (low) to 15.2 °C (high). Annual precipitation averages 3866.4 Millimeters. Neilton 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 | 1.7 °C | 7.5 °C | 651.26 mm |
| February | 1.4 °C | 9.1 °C | 337.82 mm |
| March | 2.4 °C | 11.1 °C | 452.88 mm |
| April | 3.8 °C | 14.7 °C | 286.77 mm |
| May | 6.6 °C | 18.1 °C | 163.07 mm |
| June | 8.9 °C | 20.7 °C | 104.39 mm |
| July | 10.7 °C | 23.7 °C | 48.26 mm |
| August | 10.9 °C | 24.1 °C | 90.42 mm |
| September | 9.3 °C | 21.7 °C | 126.75 mm |
| October | 6.3 °C | 15.1 °C | 373.89 mm |
| November | 3.3 °C | 9.9 °C | 573.79 mm |
| December | 1.5 °C | 6.8 °C | 657.1 mm |
| Annual | 5.6 °C | 15.2 °C | 3866.4 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 | Abnormally Dry |
| Köppen Climate Classification | Cfb - Temperate Oceanic Climate |