Merlin, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 42.3 °F (low) to 67.8 °F (high). Annual precipitation averages 38.3 Inches. Merlin 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 | 34.0 °F | 48.2 °F | 6.95 in. |
| February | 34.5 °F | 54.2 °F | 4.79 in. |
| March | 36.2 °F | 59.3 °F | 4.67 in. |
| April | 39.4 °F | 64.8 °F | 2.88 in. |
| May | 44.6 °F | 73.5 °F | 1.95 in. |
| June | 49.5 °F | 80.5 °F | 0.6 in. |
| July | 55.0 °F | 89.6 °F | 0.31 in. |
| August | 53.9 °F | 89.9 °F | 0.17 in. |
| September | 47.7 °F | 83.4 °F | 0.56 in. |
| October | 40.9 °F | 69.4 °F | 2.48 in. |
| November | 37.8 °F | 54.4 °F | 5.48 in. |
| December | 34.2 °F | 46.0 °F | 7.46 in. |
| Annual | 42.3 °F | 67.8 °F | 38.3 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 | Severe Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |