Sublette, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38.1 °F (low) to 58.6 °F (high). Annual precipitation averages 38 Inches. 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 | 12.2 °F | 28.9 °F | 1.74 in. |
| February | 16.1 °F | 33.4 °F | 1.73 in. |
| March | 26.1 °F | 45.9 °F | 2.35 in. |
| April | 36.5 °F | 59.6 °F | 3.57 in. |
| May | 48.4 °F | 71.2 °F | 4.78 in. |
| June | 58.3 °F | 79.9 °F | 5.02 in. |
| July | 61.6 °F | 82.9 °F | 4.12 in. |
| August | 59.5 °F | 81.2 °F | 3.93 in. |
| September | 51.3 °F | 75.5 °F | 3.49 in. |
| October | 39.6 °F | 62.6 °F | 2.89 in. |
| November | 28.7 °F | 47.2 °F | 2.39 in. |
| December | 18.5 °F | 34.3 °F | 1.97 in. |
| Annual | 38.1 °F | 58.6 °F | 37.98 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 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |