Joppa, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 47.7 °F (low) to 67.8 °F (high). Annual precipitation averages 51.1 Inches. Joppa 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 | 26.3 °F | 43.1 °F | 4.13 in. |
| February | 29.3 °F | 47.7 °F | 3.53 in. |
| March | 37.2 °F | 57.5 °F | 4.75 in. |
| April | 47.0 °F | 68.9 °F | 5.14 in. |
| May | 57.3 °F | 77.5 °F | 5.35 in. |
| June | 65.8 °F | 85.6 °F | 4.73 in. |
| July | 69.2 °F | 88.6 °F | 4.01 in. |
| August | 67.0 °F | 87.4 °F | 3.02 in. |
| September | 59.1 °F | 81.8 °F | 3.57 in. |
| October | 47.4 °F | 70.9 °F | 3.91 in. |
| November | 37.1 °F | 57.5 °F | 4.37 in. |
| December | 29.9 °F | 46.6 °F | 4.59 in. |
| Annual | 47.7 °F | 67.8 °F | 51.1 in. |
| 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 : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |