Downs, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.3 °C (low) to 16.3 °C (high). Annual precipitation averages 993.1 Millimeters. Downs is located in USDA Plant Hardiness Zone 6a. 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 | -8.7 °C | 0.3 °C | 56.64 mm |
| February | -6.7 °C | 3 °C | 49.78 mm |
| March | -1.6 °C | 9.6 °C | 67.82 mm |
| April | 4.6 °C | 16.9 °C | 96.77 mm |
| May | 11.1 °C | 22.9 °C | 111.76 mm |
| June | 16.3 °C | 27.8 °C | 110.74 mm |
| July | 18.1 °C | 29.4 °C | 103.38 mm |
| August | 16.9 °C | 28.4 °C | 92.71 mm |
| September | 12.6 °C | 25.6 °C | 86.11 mm |
| October | 6.2 °C | 18.4 °C | 86.61 mm |
| November | -0.2 °C | 10.2 °C | 71.37 mm |
| December | -5.4 °C | 3.1 °C | 59.44 mm |
| Annual | 5.3 °C | 16.3 °C | 993.13 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 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 |