Dongola, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 47 °F (low) to 67.5 °F (high). Annual precipitation averages 49.9 Inches. Dongola is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 25.3 °F | 42.4 °F | 3.7 in. |
| February | 28.4 °F | 47.6 °F | 3.44 in. |
| March | 36.5 °F | 57.2 °F | 4.68 in. |
| April | 46.5 °F | 68.5 °F | 5.38 in. |
| May | 56.8 °F | 77.1 °F | 5.43 in. |
| June | 65.2 °F | 85.5 °F | 4.53 in. |
| July | 68.7 °F | 88.4 °F | 3.91 in. |
| August | 66.3 °F | 87.5 °F | 3.0 in. |
| September | 58.2 °F | 81.8 °F | 3.41 in. |
| October | 46.6 °F | 71.0 °F | 3.82 in. |
| November | 36.6 °F | 57.2 °F | 4.47 in. |
| December | 29.1 °F | 46.1 °F | 4.08 in. |
| Annual | 47 °F | 67.5 °F | 49.85 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| 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 |