Sparland, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.2 °F (low) to 61.6 °F (high). Annual precipitation averages 38.3 Inches. Sparland is located in USDA Plant Hardiness Zone 5b. 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 | 16.1 °F | 32.3 °F | 2.08 in. |
| February | 19.5 °F | 36.7 °F | 1.92 in. |
| March | 29.3 °F | 49.2 °F | 2.59 in. |
| April | 39.9 °F | 62.7 °F | 3.89 in. |
| May | 51.2 °F | 73.6 °F | 4.88 in. |
| June | 60.9 °F | 82.5 °F | 4.16 in. |
| July | 64.5 °F | 85.6 °F | 3.79 in. |
| August | 62.5 °F | 84.1 °F | 3.64 in. |
| September | 54.2 °F | 78.4 °F | 3.42 in. |
| October | 42.5 °F | 65.7 °F | 3.18 in. |
| November | 31.6 °F | 50.3 °F | 2.65 in. |
| December | 21.9 °F | 37.5 °F | 2.07 in. |
| Annual | 41.2 °F | 61.6 °F | 38.27 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |