Machias, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 42.7 °F (low) to 59.7 °F (high). Annual precipitation averages 47.6 Inches. Machias 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 | 34.4 °F | 46.3 °F | 6.19 in. |
| February | 34.4 °F | 49.4 °F | 4.32 in. |
| March | 36.8 °F | 53.5 °F | 5.01 in. |
| April | 40.6 °F | 58.1 °F | 4.06 in. |
| May | 45.8 °F | 64.7 °F | 2.91 in. |
| June | 50.2 °F | 68.6 °F | 2.75 in. |
| July | 53.3 °F | 74.5 °F | 1.13 in. |
| August | 53.2 °F | 75.4 °F | 1.1 in. |
| September | 49.1 °F | 70.2 °F | 2.51 in. |
| October | 43.0 °F | 59.6 °F | 4.72 in. |
| November | 37.8 °F | 50.9 °F | 6.81 in. |
| December | 34.2 °F | 45.4 °F | 6.11 in. |
| Annual | 42.7 °F | 59.7 °F | 47.62 in. |
| 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 : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |