Leonore, 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 15.9 °C (high). Annual precipitation averages 946.4 Millimeters. Leonore is located in USDA Plant Hardiness Zone 5b. 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 | -9.1 °C | -0.3 °C | 48.26 mm |
| February | -7.1 °C | 2.2 °C | 45.47 mm |
| March | -1.8 °C | 9.1 °C | 62.74 mm |
| April | 4 °C | 16.6 °C | 90.17 mm |
| May | 10.6 °C | 22.7 °C | 116.84 mm |
| June | 15.9 °C | 27.6 °C | 111 mm |
| July | 17.9 °C | 29.2 °C | 98.3 mm |
| August | 16.7 °C | 28.2 °C | 93.98 mm |
| September | 12.2 °C | 25.3 °C | 86.11 mm |
| October | 5.7 °C | 18.3 °C | 76.45 mm |
| November | -0.4 °C | 9.7 °C | 65.28 mm |
| December | -5.8 °C | 2.7 °C | 51.82 mm |
| Annual | 4.9 °C | 15.9 °C | 946.42 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 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 |