Mehama, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.8 °C (low) to 16.7 °C (high). Annual precipitation averages 1723.2 Millimeters. Mehama 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 | 1.3 °C | 8.2 °C | 223.27 mm |
| February | 1.6 °C | 9.9 °C | 174.5 mm |
| March | 2.8 °C | 12.2 °C | 196.85 mm |
| April | 4.6 °C | 15.2 °C | 169.93 mm |
| May | 7.1 °C | 19.2 °C | 118.36 mm |
| June | 9.6 °C | 22.2 °C | 76.71 mm |
| July | 11.6 °C | 27 °C | 15.75 mm |
| August | 11.5 °C | 27.6 °C | 17.53 mm |
| September | 9.1 °C | 24 °C | 73.66 mm |
| October | 6.2 °C | 17.1 °C | 147.07 mm |
| November | 3.3 °C | 10.7 °C | 231.9 mm |
| December | 1.2 °C | 7.4 °C | 277.62 mm |
| Annual | 5.8 °C | 16.7 °C | 1723.15 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 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 |