Prairie City, Oregon has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.1 °C (low) to 15.7 °C (high). Annual precipitation averages 353.6 Millimeters. Prairie City 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 | -6.3 °C | 4.3 °C | 32.51 mm |
| February | -5.3 °C | 6.6 °C | 22.61 mm |
| March | -3.1 °C | 10.3 °C | 32.77 mm |
| April | -1 °C | 13.4 °C | 38.61 mm |
| May | 2.5 °C | 18.4 °C | 52.07 mm |
| June | 5.4 °C | 22.9 °C | 35.56 mm |
| July | 8.2 °C | 29.7 °C | 14.99 mm |
| August | 7.4 °C | 29.4 °C | 11.68 mm |
| September | 3.8 °C | 24.6 °C | 14.48 mm |
| October | -0.4 °C | 16.7 °C | 29.21 mm |
| November | -3.7 °C | 8.6 °C | 34.54 mm |
| December | -6.6 °C | 3.7 °C | 34.54 mm |
| Annual | 0.1 °C | 15.7 °C | 353.57 mm |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |