Halfway, Oregon has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 34.8 °F (low) to 62.6 °F (high). Annual precipitation averages 21.3 Inches. Halfway is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.8 °F | 35.3 °F | 3.51 in. |
| February | 22.9 °F | 42.1 °F | 2.19 in. |
| March | 28.9 °F | 53.0 °F | 1.84 in. |
| April | 33.4 °F | 61.8 °F | 1.56 in. |
| May | 40.3 °F | 71.5 °F | 1.79 in. |
| June | 46.5 °F | 79.4 °F | 1.31 in. |
| July | 52.3 °F | 90.6 °F | 0.46 in. |
| August | 50.5 °F | 90.0 °F | 0.33 in. |
| September | 42.5 °F | 80.0 °F | 0.66 in. |
| October | 33.5 °F | 64.0 °F | 1.3 in. |
| November | 26.3 °F | 47.1 °F | 2.51 in. |
| December | 20.7 °F | 36.3 °F | 3.79 in. |
| Annual | 34.8 °F | 62.6 °F | 21.25 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |