Roodhouse, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6 °C (low) to 17.3 °C (high). Annual precipitation averages 1014.5 Millimeters. Roodhouse is located in USDA Plant Hardiness Zone 6a. 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 | -7.4 °C | 1.9 °C | 54.36 mm |
| February | -5.5 °C | 4.8 °C | 52.07 mm |
| March | -0.3 °C | 11.1 °C | 74.68 mm |
| April | 5.4 °C | 17.8 °C | 109.73 mm |
| May | 11.8 °C | 23.4 °C | 124.46 mm |
| June | 16.9 °C | 28.2 °C | 121.41 mm |
| July | 18.7 °C | 29.8 °C | 98.55 mm |
| August | 17.4 °C | 29.3 °C | 84.84 mm |
| September | 12.7 °C | 26.2 °C | 79.5 mm |
| October | 6.3 °C | 19.3 °C | 76.45 mm |
| November | 0.6 °C | 11.4 °C | 78.74 mm |
| December | -4.6 °C | 4.7 °C | 59.69 mm |
| Annual | 6 °C | 17.3 °C | 1014.48 mm |
| 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 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |