Greenwood, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38.4 °F (low) to 57.9 °F (high). Annual precipitation averages 38.2 Inches. Greenwood is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.7 °F | 29.3 °F | 1.77 in. |
| February | 16.5 °F | 33.4 °F | 1.87 in. |
| March | 25.8 °F | 44.9 °F | 2.23 in. |
| April | 36.0 °F | 57.6 °F | 3.83 in. |
| May | 47.4 °F | 69.2 °F | 4.56 in. |
| June | 57.1 °F | 78.9 °F | 4.97 in. |
| July | 61.6 °F | 82.9 °F | 3.89 in. |
| August | 59.9 °F | 81.1 °F | 3.91 in. |
| September | 52.1 °F | 74.5 °F | 3.61 in. |
| October | 40.8 °F | 61.3 °F | 3.09 in. |
| November | 30.1 °F | 47.0 °F | 2.46 in. |
| December | 19.7 °F | 34.4 °F | 2.01 in. |
| Annual | 38.4 °F | 57.9 °F | 38.2 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |