De Soto, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.1 °F (low) to 66.6 °F (high). Annual precipitation averages 47.1 Inches. De Soto 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 | 23.9 °F | 40.9 °F | 3.24 in. |
| February | 27.2 °F | 45.9 °F | 3.04 in. |
| March | 35.5 °F | 56.0 °F | 4.25 in. |
| April | 45.7 °F | 67.3 °F | 5.33 in. |
| May | 56.1 °F | 76.4 °F | 5.26 in. |
| June | 64.8 °F | 85.2 °F | 4.56 in. |
| July | 68.3 °F | 88.0 °F | 3.83 in. |
| August | 65.6 °F | 87.0 °F | 3.08 in. |
| September | 57.1 °F | 81.2 °F | 3.19 in. |
| October | 45.5 °F | 69.9 °F | 3.62 in. |
| November | 35.7 °F | 56.2 °F | 4.19 in. |
| December | 27.9 °F | 45.1 °F | 3.52 in. |
| Annual | 46.1 °F | 66.6 °F | 47.11 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 | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |