Parkersburg, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 45.2 °F (low) to 65.7 °F (high). Annual precipitation averages 46.7 Inches. Parkersburg 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 | 22.7 °F | 38.9 °F | 3.42 in. |
| February | 25.5 °F | 43.9 °F | 2.63 in. |
| March | 34.1 °F | 54.4 °F | 3.96 in. |
| April | 44.4 °F | 66.5 °F | 5.02 in. |
| May | 55.2 °F | 76.2 °F | 5.14 in. |
| June | 64.2 °F | 84.8 °F | 4.87 in. |
| July | 66.9 °F | 87.7 °F | 4.36 in. |
| August | 64.7 °F | 86.8 °F | 3.05 in. |
| September | 56.8 °F | 81.4 °F | 3.32 in. |
| October | 45.4 °F | 69.4 °F | 3.59 in. |
| November | 34.9 °F | 54.8 °F | 3.99 in. |
| December | 27.0 °F | 43.2 °F | 3.38 in. |
| Annual | 45.2 °F | 65.7 °F | 46.73 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |