Sublette, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.4 °C (low) to 14.8 °C (high). Annual precipitation averages 964.7 Millimeters. Sublette is located in USDA Plant Hardiness Zone 5b. 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 °C | -1.7 °C | 44.2 mm |
| February | -8.8 °C | 0.8 °C | 43.94 mm |
| March | -3.3 °C | 7.7 °C | 59.69 mm |
| April | 2.5 °C | 15.3 °C | 90.68 mm |
| May | 9.1 °C | 21.8 °C | 121.41 mm |
| June | 14.6 °C | 26.6 °C | 127.51 mm |
| July | 16.4 °C | 28.3 °C | 104.65 mm |
| August | 15.3 °C | 27.3 °C | 99.82 mm |
| September | 10.7 °C | 24.2 °C | 88.65 mm |
| October | 4.2 °C | 17 °C | 73.41 mm |
| November | -1.8 °C | 8.4 °C | 60.71 mm |
| December | -7.5 °C | 1.3 °C | 50.04 mm |
| Annual | 3.4 °C | 14.8 °C | 964.71 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 5b : -26.1°C to -23.3°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 |