Holley, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.6 °C (low) to 17.2 °C (high). Annual precipitation averages 1285.2 Millimeters. Holley 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. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.3 °C | 8.3 °C | 177.55 mm |
| February | 1.5 °C | 10.4 °C | 138.43 mm |
| March | 2.6 °C | 12.9 °C | 150.62 mm |
| April | 4.2 °C | 15.8 °C | 118.36 mm |
| May | 6.9 °C | 19.5 °C | 80.52 mm |
| June | 9.2 °C | 22.6 °C | 51.82 mm |
| July | 11.1 °C | 27.6 °C | 10.92 mm |
| August | 10.9 °C | 28.1 °C | 13.72 mm |
| September | 8.8 °C | 24.7 °C | 42.16 mm |
| October | 5.9 °C | 18 °C | 106.93 mm |
| November | 3.3 °C | 11.2 °C | 182.12 mm |
| December | 1.2 °C | 7.7 °C | 212.09 mm |
| Annual | 5.6 °C | 17.2 °C | 1285.24 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| 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 |