The Dalles, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.9 °C (low) to 18.2 °C (high). Annual precipitation averages 368.5 Millimeters. The Dalles is located in USDA Plant Hardiness Zone 8a. 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 | -0.7 °C | 5.8 °C | 72.39 mm |
| February | -0.2 °C | 9.2 °C | 33.27 mm |
| March | 1.9 °C | 13.5 °C | 37.85 mm |
| April | 4.7 °C | 17.6 °C | 17.27 mm |
| May | 8.3 °C | 22.5 °C | 20.07 mm |
| June | 11.4 °C | 25.8 °C | 11.43 mm |
| July | 14.3 °C | 30.7 °C | 4.06 mm |
| August | 14.1 °C | 30.9 °C | 5.84 mm |
| September | 10 °C | 26.7 °C | 7.87 mm |
| October | 5.3 °C | 19 °C | 28.45 mm |
| November | 1.7 °C | 10.6 °C | 53.59 mm |
| December | -0.6 °C | 5.7 °C | 76.45 mm |
| Annual | 5.9 °C | 18.2 °C | 368.54 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 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |