Rittman, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 41 °F (low) to 59.7 °F (high). Annual precipitation averages 39.8 Inches. Rittman 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 | 19.1 °F | 33.9 °F | 2.76 in. |
| February | 20.3 °F | 36.7 °F | 2.07 in. |
| March | 28.2 °F | 46.4 °F | 2.96 in. |
| April | 38.9 °F | 59.8 °F | 3.67 in. |
| May | 49.6 °F | 70.3 °F | 4.04 in. |
| June | 58.8 °F | 78.9 °F | 4.26 in. |
| July | 62.4 °F | 82.5 °F | 4.02 in. |
| August | 60.7 °F | 81.1 °F | 3.75 in. |
| September | 53.4 °F | 75.0 °F | 3.48 in. |
| October | 42.6 °F | 62.7 °F | 3.21 in. |
| November | 33.1 °F | 49.9 °F | 2.85 in. |
| December | 25.1 °F | 38.7 °F | 2.77 in. |
| Annual | 41 °F | 59.7 °F | 39.84 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 100-125 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 |