Sparland, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.1 °C (low) to 16.4 °C (high). Annual precipitation averages 972.1 Millimeters. 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 | -8.8 °C | 0.2 °C | 52.83 mm |
| February | -6.9 °C | 2.6 °C | 48.77 mm |
| March | -1.5 °C | 9.6 °C | 65.79 mm |
| April | 4.4 °C | 17.1 °C | 98.81 mm |
| May | 10.7 °C | 23.1 °C | 123.95 mm |
| June | 16.1 °C | 28.1 °C | 105.66 mm |
| July | 18.1 °C | 29.8 °C | 96.27 mm |
| August | 16.9 °C | 28.9 °C | 92.46 mm |
| September | 12.3 °C | 25.8 °C | 86.87 mm |
| October | 5.8 °C | 18.7 °C | 80.77 mm |
| November | -0.2 °C | 10.2 °C | 67.31 mm |
| December | -5.6 °C | 3.1 °C | 52.58 mm |
| Annual | 5.1 °C | 16.4 °C | 972.07 mm |
| 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 : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |