Halsey, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 42.5 °F (low) to 63.5 °F (high). Annual precipitation averages 39.7 Inches. Halsey 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 | 35.1 °F | 47.4 °F | 5.62 in. |
| February | 35.2 °F | 51.2 °F | 4.49 in. |
| March | 37.3 °F | 55.9 °F | 4.68 in. |
| April | 40.1 °F | 60.7 °F | 3.35 in. |
| May | 44.8 °F | 67.4 °F | 2.42 in. |
| June | 48.8 °F | 73.3 °F | 1.44 in. |
| July | 52.5 °F | 82.1 °F | 0.36 in. |
| August | 52.3 °F | 82.8 °F | 0.5 in. |
| September | 48.4 °F | 77.0 °F | 1.42 in. |
| October | 42.6 °F | 64.3 °F | 3.29 in. |
| November | 38.2 °F | 52.9 °F | 5.74 in. |
| December | 34.7 °F | 46.4 °F | 6.39 in. |
| Annual | 42.5 °F | 63.5 °F | 39.7 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| 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 | Severe Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |