Cedarville, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37.7 °F (low) to 57.7 °F (high). Annual precipitation averages 38.1 Inches. Cedarville is located in USDA Plant Hardiness Zone 5a. 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 | 11.5 °F | 28.2 °F | 1.5 in. |
| February | 14.9 °F | 32.5 °F | 1.64 in. |
| March | 25.5 °F | 44.8 °F | 2.06 in. |
| April | 36.3 °F | 58.5 °F | 3.66 in. |
| May | 48.0 °F | 70.0 °F | 4.36 in. |
| June | 58.1 °F | 79.4 °F | 5.48 in. |
| July | 61.6 °F | 82.3 °F | 4.38 in. |
| August | 59.5 °F | 80.8 °F | 3.96 in. |
| September | 50.9 °F | 74.3 °F | 4.0 in. |
| October | 39.5 °F | 61.6 °F | 2.94 in. |
| November | 28.5 °F | 46.3 °F | 2.24 in. |
| December | 18.0 °F | 33.6 °F | 1.84 in. |
| Annual | 37.7 °F | 57.7 °F | 38.06 in. |
| 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |