Grants Pass, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.7 °C (low) to 19.9 °C (high). Annual precipitation averages 819.4 Millimeters. Grants Pass is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.1 °C | 8.8 °C | 135.89 mm |
| February | 1.4 °C | 12.3 °C | 101.6 mm |
| March | 2.3 °C | 15.2 °C | 96.01 mm |
| April | 4.1 °C | 18.3 °C | 58.67 mm |
| May | 7 °C | 23.2 °C | 32.77 mm |
| June | 9.8 °C | 27 °C | 17.53 mm |
| July | 12.8 °C | 32.1 °C | 9.14 mm |
| August | 12.1 °C | 32.2 °C | 6.1 mm |
| September | 8.7 °C | 28.6 °C | 15.49 mm |
| October | 4.9 °C | 20.8 °C | 55.12 mm |
| November | 3.2 °C | 12.3 °C | 116.33 mm |
| December | 1.2 °C | 7.7 °C | 174.75 mm |
| Annual | 5.7 °C | 19.9 °C | 819.4 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 | Severe Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |