Piper City, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.8 °C (low) to 16.4 °C (high). Annual precipitation averages 995.4 Millimeters. Piper City is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.8 °C | 0.3 °C | 59.94 mm |
| February | -7.1 °C | 2.8 °C | 50.04 mm |
| March | -1.8 °C | 9.6 °C | 66.8 mm |
| April | 3.9 °C | 17.1 °C | 98.04 mm |
| May | 10.3 °C | 23.2 °C | 115.82 mm |
| June | 15.8 °C | 28 °C | 114.05 mm |
| July | 17.6 °C | 29.6 °C | 112.78 mm |
| August | 16.3 °C | 28.6 °C | 94.49 mm |
| September | 11.7 °C | 25.9 °C | 74.17 mm |
| October | 5.5 °C | 18.8 °C | 83.82 mm |
| November | -0.4 °C | 10.2 °C | 72.14 mm |
| December | -5.8 °C | 3.1 °C | 53.34 mm |
| Annual | 4.8 °C | 16.4 °C | 995.43 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |