Ridgway, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.6 °F (low) to 66.9 °F (high). Annual precipitation averages 47 Inches. Ridgway is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 25.2 °F | 41.3 °F | 3.6 in. |
| February | 27.8 °F | 46.3 °F | 3.2 in. |
| March | 35.8 °F | 56.0 °F | 4.47 in. |
| April | 45.9 °F | 67.8 °F | 4.92 in. |
| May | 56.5 °F | 76.8 °F | 5.11 in. |
| June | 64.9 °F | 85.1 °F | 4.37 in. |
| July | 68.0 °F | 88.0 °F | 4.07 in. |
| August | 65.7 °F | 87.1 °F | 3.0 in. |
| September | 58.2 °F | 82.0 °F | 3.14 in. |
| October | 46.6 °F | 70.2 °F | 3.34 in. |
| November | 36.1 °F | 56.4 °F | 4.0 in. |
| December | 28.8 °F | 45.7 °F | 3.81 in. |
| Annual | 46.6 °F | 66.9 °F | 47.03 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |