Altamont, Oregon has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 0.1 °C (low) to 16 °C (high). Annual precipitation averages 340.4 Millimeters. Altamont is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.8 °C | 4.9 °C | 50.04 mm |
| February | -4.6 °C | 7.3 °C | 35.81 mm |
| March | -2.9 °C | 10.3 °C | 33.53 mm |
| April | -1.3 °C | 13.6 °C | 27.94 mm |
| May | 2.3 °C | 18.8 °C | 28.96 mm |
| June | 5.1 °C | 23.5 °C | 16.76 mm |
| July | 8.4 °C | 29.2 °C | 6.35 mm |
| August | 7.4 °C | 28.7 °C | 8.89 mm |
| September | 3.6 °C | 24.9 °C | 9.65 mm |
| October | -0.9 °C | 17.6 °C | 22.1 mm |
| November | -3.8 °C | 9.2 °C | 39.88 mm |
| December | -6.3 °C | 4.2 °C | 60.45 mm |
| Annual | 0.1 °C | 16 °C | 340.36 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |