Perry, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.8 °F (low) to 63.3 °F (high). Annual precipitation averages 39.1 Inches. 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 | 18.5 °F | 35.4 °F | 2.06 in. |
| February | 22.1 °F | 40.5 °F | 1.9 in. |
| March | 31.4 °F | 51.8 °F | 2.71 in. |
| April | 42.0 °F | 64.4 °F | 4.01 in. |
| May | 53.0 °F | 74.2 °F | 4.53 in. |
| June | 62.3 °F | 82.9 °F | 4.71 in. |
| July | 65.9 °F | 86.5 °F | 4.27 in. |
| August | 63.5 °F | 85.3 °F | 3.28 in. |
| September | 54.9 °F | 79.0 °F | 3.65 in. |
| October | 43.6 °F | 67.0 °F | 2.99 in. |
| November | 33.1 °F | 52.7 °F | 2.85 in. |
| December | 23.8 °F | 40.2 °F | 2.15 in. |
| Annual | 42.8 °F | 63.3 °F | 39.11 in. |
| 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 : -10°F to -5°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 |