Butler, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.7 °C (low) to 17.9 °C (high). Annual precipitation averages 1061.7 Millimeters. Butler is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.4 °C | 2.3 °C | 69.34 mm |
| February | -4.4 °C | 5.2 °C | 56.13 mm |
| March | 0.6 °C | 11.4 °C | 77.47 mm |
| April | 6.3 °C | 18.6 °C | 124.46 mm |
| May | 12.4 °C | 24.1 °C | 130.3 mm |
| June | 17.3 °C | 28.9 °C | 111 mm |
| July | 19.1 °C | 30.6 °C | 96.77 mm |
| August | 17.8 °C | 29.9 °C | 83.31 mm |
| September | 13.3 °C | 26.8 °C | 75.95 mm |
| October | 6.9 °C | 20.1 °C | 84.84 mm |
| November | 1.4 °C | 11.6 °C | 87.63 mm |
| December | -3.6 °C | 5.1 °C | 64.52 mm |
| Annual | 6.7 °C | 17.9 °C | 1061.72 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |