Nooksack, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.7 °C (low) to 15.4 °C (high). Annual precipitation averages 1197.4 Millimeters. Nooksack is located in USDA Plant Hardiness Zone 8a. 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 | 0.7 °C | 6.9 °C | 157.99 mm |
| February | 1.2 °C | 8.8 °C | 92.96 mm |
| March | 2.6 °C | 11.3 °C | 123.44 mm |
| April | 4.6 °C | 14.8 °C | 97.28 mm |
| May | 7.6 °C | 18.7 °C | 78.23 mm |
| June | 10.2 °C | 21.1 °C | 58.67 mm |
| July | 11.6 °C | 24.3 °C | 36.58 mm |
| August | 11.3 °C | 24.9 °C | 34.04 mm |
| September | 8.9 °C | 21.6 °C | 67.06 mm |
| October | 5.9 °C | 15.4 °C | 131.83 mm |
| November | 3 °C | 9.9 °C | 172.72 mm |
| December | 0.6 °C | 6.6 °C | 146.56 mm |
| Annual | 5.7 °C | 15.4 °C | 1197.36 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 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |