Athens, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.9 °C (low) to 17.1 °C (high). Annual precipitation averages 985.3 Millimeters. Athens is located in USDA Plant Hardiness Zone 6a. 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 | -7.7 °C | 1.6 °C | 54.1 mm |
| February | -5.8 °C | 4.3 °C | 48.77 mm |
| March | -0.7 °C | 10.8 °C | 67.31 mm |
| April | 5.3 °C | 17.9 °C | 101.35 mm |
| May | 11.7 °C | 23.4 °C | 115.57 mm |
| June | 16.9 °C | 28 °C | 116.08 mm |
| July | 18.6 °C | 29.7 °C | 96.27 mm |
| August | 17.3 °C | 28.9 °C | 88.9 mm |
| September | 12.7 °C | 26.1 °C | 81.79 mm |
| October | 6.3 °C | 19.2 °C | 82.3 mm |
| November | 0.3 °C | 11.1 °C | 76.71 mm |
| December | -4.6 °C | 4.5 °C | 56.13 mm |
| Annual | 5.9 °C | 17.1 °C | 985.28 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 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 |