Harbor, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 47 °F (low) to 60.8 °F (high). Annual precipitation averages 79 Inches. Harbor is located in USDA Plant Hardiness Zone 10a. The growing season typically runs from the last frost around Jan. 21 - Jan. 31 through the first frost around Jan. 1 - Jan. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 42.9 °F | 54.4 °F | 12.74 in. |
| February | 42.8 °F | 55.5 °F | 9.71 in. |
| March | 43.0 °F | 56.6 °F | 10.43 in. |
| April | 44.5 °F | 58.6 °F | 7.43 in. |
| May | 47.4 °F | 62.2 °F | 3.55 in. |
| June | 50.0 °F | 65.3 °F | 2.18 in. |
| July | 52.3 °F | 67.0 °F | 0.37 in. |
| August | 52.9 °F | 66.3 °F | 0.56 in. |
| September | 51.2 °F | 67.6 °F | 1.46 in. |
| October | 48.7 °F | 64.2 °F | 5.41 in. |
| November | 45.5 °F | 57.6 °F | 10.67 in. |
| December | 42.6 °F | 54.2 °F | 14.53 in. |
| Annual | 47 °F | 60.8 °F | 79.04 in. |
| Average First Frost Date | Jan. 1 - Jan. 10 |
| Average Last Frost Date | Jan. 21 - Jan. 31 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 10a : 30°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 9b : 25°F to 20°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |