Scappoose, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 43.8 °F (low) to 62.9 °F (high). Annual precipitation averages 43.4 Inches. Scappoose 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. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.2 °F | 46.5 °F | 6.48 in. |
| February | 35.2 °F | 50.5 °F | 4.66 in. |
| March | 37.9 °F | 55.5 °F | 4.99 in. |
| April | 40.9 °F | 60.9 °F | 3.49 in. |
| May | 46.6 °F | 68.0 °F | 2.42 in. |
| June | 50.8 °F | 72.8 °F | 1.47 in. |
| July | 55.1 °F | 80.6 °F | 0.44 in. |
| August | 55.1 °F | 81.8 °F | 0.52 in. |
| September | 50.5 °F | 75.9 °F | 1.51 in. |
| October | 44.0 °F | 63.6 °F | 3.62 in. |
| November | 38.8 °F | 52.5 °F | 6.39 in. |
| December | 35.0 °F | 45.8 °F | 7.41 in. |
| Annual | 43.8 °F | 62.9 °F | 43.4 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |