Spencer, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.9 °C (low) to 15.4 °C (high). Annual precipitation averages 1014 Millimeters. 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 | -7.4 °C | 0.9 °C | 71.37 mm |
| February | -6.7 °C | 2.4 °C | 54.61 mm |
| March | -2.3 °C | 7.7 °C | 74.17 mm |
| April | 3.6 °C | 15.3 °C | 94.74 mm |
| May | 9.6 °C | 21.3 °C | 102.62 mm |
| June | 14.9 °C | 26.2 °C | 107.19 mm |
| July | 16.9 °C | 28.2 °C | 102.11 mm |
| August | 15.9 °C | 27.4 °C | 94.23 mm |
| September | 11.8 °C | 24 °C | 88.65 mm |
| October | 5.9 °C | 17.2 °C | 81.28 mm |
| November | 0.7 °C | 9.9 °C | 73.66 mm |
| December | -4 °C | 3.7 °C | 69.34 mm |
| Annual | 4.9 °C | 15.4 °C | 1013.97 mm |
| 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 : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |