Selma, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 4.5 °C (low) to 20.6 °C (high). Annual precipitation averages 1274.6 Millimeters. Selma 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 | 0.2 °C | 9.4 °C | 237.74 mm |
| February | 0.6 °C | 12.6 °C | 170.94 mm |
| March | 1.4 °C | 15.2 °C | 172.47 mm |
| April | 2.9 °C | 18.4 °C | 90.17 mm |
| May | 5.8 °C | 23.5 °C | 52.07 mm |
| June | 8.4 °C | 27.9 °C | 20.57 mm |
| July | 11.2 °C | 33.6 °C | 11.68 mm |
| August | 10.1 °C | 33.4 °C | 5.59 mm |
| September | 7.2 °C | 29.9 °C | 16 mm |
| October | 3.7 °C | 21.8 °C | 71.37 mm |
| November | 2.2 °C | 12.7 °C | 183.64 mm |
| December | 0.4 °C | 8.4 °C | 242.32 mm |
| Annual | 4.5 °C | 20.6 °C | 1274.56 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 75-100 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 |