Richland, Oregon has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 37.3 °F (low) to 64.6 °F (high). Annual precipitation averages 12.8 Inches. Richland is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 22.3 °F | 37.4 °F | 1.69 in. |
| February | 25.4 °F | 44.7 °F | 1.01 in. |
| March | 30.8 °F | 55.1 °F | 1.03 in. |
| April | 35.4 °F | 63.3 °F | 1.36 in. |
| May | 42.9 °F | 73.5 °F | 1.36 in. |
| June | 49.4 °F | 81.6 °F | 1.23 in. |
| July | 55.5 °F | 92.4 °F | 0.35 in. |
| August | 53.7 °F | 92.0 °F | 0.36 in. |
| September | 45.2 °F | 81.9 °F | 0.49 in. |
| October | 35.7 °F | 65.8 °F | 0.9 in. |
| November | 27.6 °F | 48.7 °F | 1.22 in. |
| December | 23.2 °F | 38.4 °F | 1.83 in. |
| Annual | 37.3 °F | 64.6 °F | 12.83 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |