Gervais, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.4 °C (low) to 17.4 °C (high). Annual precipitation averages 1081.5 Millimeters. Gervais is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2 °C | 8.6 °C | 158.75 mm |
| February | 2.1 °C | 10.6 °C | 116.84 mm |
| March | 3.3 °C | 13.2 °C | 122.17 mm |
| April | 5.1 °C | 15.8 °C | 90.42 mm |
| May | 7.8 °C | 19.8 °C | 60.96 mm |
| June | 10.1 °C | 22.9 °C | 40.13 mm |
| July | 12.1 °C | 27.7 °C | 9.14 mm |
| August | 12 °C | 27.8 °C | 11.43 mm |
| September | 10 °C | 24.6 °C | 37.59 mm |
| October | 6.7 °C | 17.7 °C | 92.46 mm |
| November | 3.9 °C | 11.6 °C | 156.72 mm |
| December | 1.7 °C | 8 °C | 184.91 mm |
| Annual | 6.4 °C | 17.4 °C | 1081.52 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 40-50 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 | Moderate Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |