Gaston, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.5 °C (low) to 17.2 °C (high). Annual precipitation averages 1147.9 Millimeters. Gaston 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 Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.9 °C | 8.2 °C | 182.63 mm |
| February | 1.9 °C | 10.3 °C | 129.29 mm |
| March | 3.3 °C | 13 °C | 126.24 mm |
| April | 4.9 °C | 15.9 °C | 84.84 mm |
| May | 7.9 °C | 20 °C | 54.36 mm |
| June | 10.3 °C | 22.8 °C | 32 mm |
| July | 12.6 °C | 27.4 °C | 7.62 mm |
| August | 12.6 °C | 27.9 °C | 11.43 mm |
| September | 10.3 °C | 24.6 °C | 34.8 mm |
| October | 6.7 °C | 17.7 °C | 92.71 mm |
| November | 3.8 °C | 11.3 °C | 173.74 mm |
| December | 1.6 °C | 7.6 °C | 218.19 mm |
| Annual | 6.5 °C | 17.2 °C | 1147.85 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| 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 | Csb - Warm-Summer Mediterranean Climate |