Spencer, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 40.8 °F (low) to 59.6 °F (high). Annual precipitation averages 39.9 Inches. Spencer is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.7 °F | 33.7 °F | 2.81 in. |
| February | 19.9 °F | 36.3 °F | 2.15 in. |
| March | 27.9 °F | 45.9 °F | 2.92 in. |
| April | 38.5 °F | 59.5 °F | 3.73 in. |
| May | 49.3 °F | 70.3 °F | 4.04 in. |
| June | 58.8 °F | 79.1 °F | 4.22 in. |
| July | 62.4 °F | 82.8 °F | 4.02 in. |
| August | 60.6 °F | 81.3 °F | 3.71 in. |
| September | 53.3 °F | 75.2 °F | 3.49 in. |
| October | 42.6 °F | 62.9 °F | 3.2 in. |
| November | 33.2 °F | 49.9 °F | 2.9 in. |
| December | 24.8 °F | 38.6 °F | 2.73 in. |
| Annual | 40.8 °F | 59.6 °F | 39.92 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 |