Sparta, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 45.9 °F (low) to 66.2 °F (high). Annual precipitation averages 45.2 Inches. Sparta is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.1 °F | 40.2 °F | 2.78 in. |
| February | 26.6 °F | 45.4 °F | 2.54 in. |
| March | 34.8 °F | 55.6 °F | 3.69 in. |
| April | 45.1 °F | 67.1 °F | 5.03 in. |
| May | 55.7 °F | 76.1 °F | 5.32 in. |
| June | 64.5 °F | 85.0 °F | 4.52 in. |
| July | 68.1 °F | 88.1 °F | 4.35 in. |
| August | 65.8 °F | 87.0 °F | 3.23 in. |
| September | 57.5 °F | 80.7 °F | 3.24 in. |
| October | 46.2 °F | 69.8 °F | 3.36 in. |
| November | 35.8 °F | 55.5 °F | 4.06 in. |
| December | 27.4 °F | 44.3 °F | 3.06 in. |
| Annual | 45.9 °F | 66.2 °F | 45.18 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |