Goreville, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.8 °C (low) to 19.3 °C (high). Annual precipitation averages 1268 Millimeters. Goreville 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.3 °C | 5.5 °C | 93.73 mm |
| February | -2.7 °C | 8.6 °C | 84.07 mm |
| March | 2.2 °C | 13.7 °C | 117.35 mm |
| April | 7.6 °C | 19.9 °C | 139.45 mm |
| May | 13.1 °C | 24.4 °C | 138.94 mm |
| June | 17.5 °C | 29.2 °C | 119.63 mm |
| July | 19.7 °C | 30.4 °C | 101.85 mm |
| August | 18.5 °C | 30.4 °C | 78.74 mm |
| September | 14.1 °C | 27.2 °C | 85.6 mm |
| October | 7.9 °C | 21.4 °C | 94.74 mm |
| November | 2.3 °C | 13.7 °C | 112.78 mm |
| December | -2.5 °C | 7.4 °C | 101.09 mm |
| Annual | 7.8 °C | 19.3 °C | 1267.97 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |