Westport, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.9 °C (low) to 15.8 °C (high). Annual precipitation averages 1590.3 Millimeters. Westport 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.7 °C | 8.2 °C | 212.6 mm |
| February | 1.4 °C | 10 °C | 166.62 mm |
| March | 2.6 °C | 12.1 °C | 189.23 mm |
| April | 4.3 °C | 14.9 °C | 167.64 mm |
| May | 7.1 °C | 18.2 °C | 74.68 mm |
| June | 9.6 °C | 20.2 °C | 44.7 mm |
| July | 11.6 °C | 23.5 °C | 18.54 mm |
| August | 11.7 °C | 24.1 °C | 28.45 mm |
| September | 9.6 °C | 22.3 °C | 65.28 mm |
| October | 6.2 °C | 16.7 °C | 148.34 mm |
| November | 3.3 °C | 11 °C | 230.38 mm |
| December | 1.5 °C | 7.8 °C | 243.84 mm |
| Annual | 5.9 °C | 15.8 °C | 1590.3 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |