Lynnville, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.8 °C (low) to 17.4 °C (high). Annual precipitation averages 1020.3 Millimeters. Lynnville is located in USDA Plant Hardiness Zone 6a. 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 | -7.7 °C | 1.7 °C | 55.37 mm |
| February | -5.7 °C | 4.6 °C | 50.29 mm |
| March | -0.6 °C | 11 °C | 73.91 mm |
| April | 5.2 °C | 18.1 °C | 105.16 mm |
| May | 11.6 °C | 23.6 °C | 123.7 mm |
| June | 16.7 °C | 28.4 °C | 128.27 mm |
| July | 18.6 °C | 30.2 °C | 102.11 mm |
| August | 17.3 °C | 29.4 °C | 85.85 mm |
| September | 12.6 °C | 26.4 °C | 86.36 mm |
| October | 6.2 °C | 19.4 °C | 76.45 mm |
| November | 0.3 °C | 11.3 °C | 75.95 mm |
| December | -4.7 °C | 4.6 °C | 56.9 mm |
| Annual | 5.8 °C | 17.4 °C | 1020.32 mm |
| 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 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |