Cedarville, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.2 °C (low) to 14.3 °C (high). Annual precipitation averages 966.7 Millimeters. 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 | -11.4 °C | -2.1 °C | 38.1 mm |
| February | -9.5 °C | 0.3 °C | 41.66 mm |
| March | -3.6 °C | 7.1 °C | 52.32 mm |
| April | 2.4 °C | 14.7 °C | 92.96 mm |
| May | 8.9 °C | 21.1 °C | 110.74 mm |
| June | 14.5 °C | 26.3 °C | 139.19 mm |
| July | 16.4 °C | 27.9 °C | 111.25 mm |
| August | 15.3 °C | 27.1 °C | 100.58 mm |
| September | 10.5 °C | 23.5 °C | 101.6 mm |
| October | 4.2 °C | 16.4 °C | 74.68 mm |
| November | -1.9 °C | 7.9 °C | 56.9 mm |
| December | -7.8 °C | 0.9 °C | 46.74 mm |
| Annual | 3.2 °C | 14.3 °C | 966.72 mm |
| 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 : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |