West Frankfort, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46 °F (low) to 66.5 °F (high). Annual precipitation averages 46.2 Inches. West Frankfort 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 | 23.8 °F | 40.7 °F | 3.27 in. |
| February | 27.0 °F | 45.6 °F | 2.93 in. |
| March | 35.4 °F | 55.8 °F | 4.13 in. |
| April | 45.4 °F | 67.5 °F | 5.3 in. |
| May | 55.9 °F | 76.4 °F | 5.16 in. |
| June | 64.5 °F | 85.0 °F | 4.53 in. |
| July | 67.9 °F | 87.9 °F | 3.86 in. |
| August | 65.4 °F | 87.2 °F | 2.97 in. |
| September | 57.5 °F | 81.2 °F | 3.11 in. |
| October | 45.8 °F | 69.7 °F | 3.45 in. |
| November | 35.8 °F | 56.2 °F | 4.14 in. |
| December | 28.1 °F | 45.1 °F | 3.39 in. |
| Annual | 46 °F | 66.5 °F | 46.24 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 | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |