Coffeen, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 44.3 °F (low) to 64.4 °F (high). Annual precipitation averages 42.3 Inches. Coffeen is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.6 °F | 36.4 °F | 2.79 in. |
| February | 24.4 °F | 41.8 °F | 2.28 in. |
| March | 33.2 °F | 52.8 °F | 3.12 in. |
| April | 43.5 °F | 65.8 °F | 4.86 in. |
| May | 54.4 °F | 75.7 °F | 5.06 in. |
| June | 63.2 °F | 84.3 °F | 4.44 in. |
| July | 66.5 °F | 87.3 °F | 3.92 in. |
| August | 64.1 °F | 86.1 °F | 3.3 in. |
| September | 56.0 °F | 80.4 °F | 3.07 in. |
| October | 44.6 °F | 68.3 °F | 3.33 in. |
| November | 34.7 °F | 53.1 °F | 3.51 in. |
| December | 25.8 °F | 41.3 °F | 2.6 in. |
| Annual | 44.3 °F | 64.4 °F | 42.28 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |