Joy, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.9 °C (low) to 15.7 °C (high). Annual precipitation averages 945.6 Millimeters. Joy 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 | -9.7 °C | -0.7 °C | 37.34 mm |
| February | -7.8 °C | 1.8 °C | 44.2 mm |
| March | -1.8 °C | 9.2 °C | 62.23 mm |
| April | 4.2 °C | 16.4 °C | 92.96 mm |
| May | 10.8 °C | 22.4 °C | 123.44 mm |
| June | 16.3 °C | 27.5 °C | 121.16 mm |
| July | 18.3 °C | 29.3 °C | 98.3 mm |
| August | 16.9 °C | 28.2 °C | 99.31 mm |
| September | 12.4 °C | 24.8 °C | 90.17 mm |
| October | 5.9 °C | 17.7 °C | 70.87 mm |
| November | -0.7 °C | 9.4 °C | 57.4 mm |
| December | -6.3 °C | 2.3 °C | 48.26 mm |
| Annual | 4.9 °C | 15.7 °C | 945.64 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 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 |