Drain, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.7 °C (low) to 18.7 °C (high). Annual precipitation averages 1208.8 Millimeters. Drain 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 | 9.7 °C | 183.9 mm |
| February | 2.1 °C | 11.9 °C | 130.81 mm |
| March | 2.9 °C | 14.6 °C | 139.95 mm |
| April | 4.3 °C | 17.2 °C | 102.11 mm |
| May | 6.7 °C | 21.1 °C | 73.91 mm |
| June | 8.9 °C | 23.9 °C | 32 mm |
| July | 11.1 °C | 29.1 °C | 7.87 mm |
| August | 10.7 °C | 29.6 °C | 10.67 mm |
| September | 8.7 °C | 26.7 °C | 31.5 mm |
| October | 5.9 °C | 19.7 °C | 84.07 mm |
| November | 3.9 °C | 12.5 °C | 181.61 mm |
| December | 1.8 °C | 8.9 °C | 230.38 mm |
| Annual | 5.7 °C | 18.7 °C | 1208.78 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 30-40 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 | Severe Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |