Congress, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 40.3 °F (low) to 59.3 °F (high). Annual precipitation averages 40.4 Inches. Congress 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 | 18.2 °F | 33.3 °F | 2.86 in. |
| February | 19.4 °F | 36.1 °F | 2.15 in. |
| March | 27.5 °F | 45.8 °F | 2.99 in. |
| April | 38.4 °F | 59.6 °F | 3.75 in. |
| May | 49.0 °F | 70.0 °F | 4.14 in. |
| June | 58.4 °F | 78.8 °F | 4.45 in. |
| July | 61.6 °F | 82.2 °F | 4.05 in. |
| August | 59.9 °F | 80.8 °F | 3.79 in. |
| September | 52.8 °F | 74.9 °F | 3.41 in. |
| October | 41.9 °F | 62.3 °F | 3.16 in. |
| November | 32.3 °F | 49.4 °F | 2.9 in. |
| December | 24.2 °F | 38.0 °F | 2.79 in. |
| Annual | 40.3 °F | 59.3 °F | 40.44 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 |