Tumalo, Oregon has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 33.5 °F (low) to 61.7 °F (high). Annual precipitation averages 12.2 Inches. Tumalo is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 24.5 °F | 42.9 °F | 1.58 in. |
| February | 24.7 °F | 46.2 °F | 1.32 in. |
| March | 27.4 °F | 52.6 °F | 0.77 in. |
| April | 30.2 °F | 58.0 °F | 0.87 in. |
| May | 36.5 °F | 66.7 °F | 1.17 in. |
| June | 41.5 °F | 74.1 °F | 1.01 in. |
| July | 47.2 °F | 84.5 °F | 0.65 in. |
| August | 46.7 °F | 84.2 °F | 0.57 in. |
| September | 40.1 °F | 76.3 °F | 0.38 in. |
| October | 32.8 °F | 63.4 °F | 0.64 in. |
| November | 27.4 °F | 49.5 °F | 1.64 in. |
| December | 23.0 °F | 41.4 °F | 1.63 in. |
| Annual | 33.5 °F | 61.7 °F | 12.23 in. |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |