Trilla, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.8 °F (low) to 63.9 °F (high). Annual precipitation averages 42.2 Inches. Trilla is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.3 °F | 36.3 °F | 2.68 in. |
| February | 23.2 °F | 41.0 °F | 2.32 in. |
| March | 32.3 °F | 52.1 °F | 3.05 in. |
| April | 42.9 °F | 64.8 °F | 4.77 in. |
| May | 54.1 °F | 74.8 °F | 4.5 in. |
| June | 63.0 °F | 83.5 °F | 4.84 in. |
| July | 65.8 °F | 86.6 °F | 4.23 in. |
| August | 63.6 °F | 85.5 °F | 2.9 in. |
| September | 55.8 °F | 80.1 °F | 3.04 in. |
| October | 44.5 °F | 67.7 °F | 3.54 in. |
| November | 33.9 °F | 52.9 °F | 3.62 in. |
| December | 25.6 °F | 41.0 °F | 2.75 in. |
| Annual | 43.8 °F | 63.9 °F | 42.24 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |