Parkman, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 39.3 °F (low) to 59 °F (high). Annual precipitation averages 43.2 Inches. Parkman is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.7 °F | 33.4 °F | 3.13 in. |
| February | 18.6 °F | 36.3 °F | 2.48 in. |
| March | 26.2 °F | 45.4 °F | 3.35 in. |
| April | 36.8 °F | 59.0 °F | 3.96 in. |
| May | 47.2 °F | 69.9 °F | 4.1 in. |
| June | 56.4 °F | 78.2 °F | 4.2 in. |
| July | 60.3 °F | 82.0 °F | 4.37 in. |
| August | 58.6 °F | 80.5 °F | 3.58 in. |
| September | 51.8 °F | 74.1 °F | 3.97 in. |
| October | 41.2 °F | 61.7 °F | 3.6 in. |
| November | 32.1 °F | 49.1 °F | 3.2 in. |
| December | 24.2 °F | 38.2 °F | 3.22 in. |
| Annual | 39.3 °F | 59 °F | 43.16 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |