Parker, Idaho has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.6 °F (low) to 55.9 °F (high). Annual precipitation averages 13.5 Inches. Parker is located in USDA Plant Hardiness Zone 5a. 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 | 10.2 °F | 28.2 °F | 1.23 in. |
| February | 13.5 °F | 32.8 °F | 0.79 in. |
| March | 22.5 °F | 44.7 °F | 0.95 in. |
| April | 29.5 °F | 55.9 °F | 1.2 in. |
| May | 37.4 °F | 65.3 °F | 1.92 in. |
| June | 43.8 °F | 73.8 °F | 1.64 in. |
| July | 48.9 °F | 83.9 °F | 0.55 in. |
| August | 47.2 °F | 83.5 °F | 0.65 in. |
| September | 39.7 °F | 73.1 °F | 0.99 in. |
| October | 30.1 °F | 58.2 °F | 1.25 in. |
| November | 20.8 °F | 41.9 °F | 1.07 in. |
| December | 12.0 °F | 29.5 °F | 1.3 in. |
| Annual | 29.6 °F | 55.9 °F | 13.54 in. |
| 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |