Perry, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6 °C (low) to 17.4 °C (high). Annual precipitation averages 993.4 Millimeters. Perry is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.5 °C | 1.9 °C | 52.32 mm |
| February | -5.5 °C | 4.7 °C | 48.26 mm |
| March | -0.3 °C | 11 °C | 68.83 mm |
| April | 5.6 °C | 18 °C | 101.85 mm |
| May | 11.7 °C | 23.4 °C | 115.06 mm |
| June | 16.8 °C | 28.3 °C | 119.63 mm |
| July | 18.8 °C | 30.3 °C | 108.46 mm |
| August | 17.5 °C | 29.6 °C | 83.31 mm |
| September | 12.7 °C | 26.1 °C | 92.71 mm |
| October | 6.4 °C | 19.4 °C | 75.95 mm |
| November | 0.6 °C | 11.5 °C | 72.39 mm |
| December | -4.6 °C | 4.6 °C | 54.61 mm |
| Annual | 6 °C | 17.4 °C | 993.38 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 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 |