Marion, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 42.9 °F (low) to 63.3 °F (high). Annual precipitation averages 46.7 Inches. Marion is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.0 °F | 47.3 °F | 6.37 in. |
| February | 35.2 °F | 51.1 °F | 4.97 in. |
| March | 37.5 °F | 55.7 °F | 5.48 in. |
| April | 40.5 °F | 60.7 °F | 4.06 in. |
| May | 45.4 °F | 67.6 °F | 2.93 in. |
| June | 49.6 °F | 73.2 °F | 1.77 in. |
| July | 53.1 °F | 81.8 °F | 0.47 in. |
| August | 52.8 °F | 82.3 °F | 0.47 in. |
| September | 49.0 °F | 76.5 °F | 1.79 in. |
| October | 43.3 °F | 64.2 °F | 4.08 in. |
| November | 38.5 °F | 52.7 °F | 6.65 in. |
| December | 34.7 °F | 46.3 °F | 7.66 in. |
| Annual | 42.9 °F | 63.3 °F | 46.7 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 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 | Moderate Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |