Dunlap, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.3 °C (low) to 16 °C (high). Annual precipitation averages 982 Millimeters. Dunlap is located in USDA Plant Hardiness Zone 5b. 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 | -9.8 °C | -0.3 °C | 51.82 mm |
| February | -7.8 °C | 2.2 °C | 50.29 mm |
| March | -2.3 °C | 9.2 °C | 64.26 mm |
| April | 3.6 °C | 16.7 °C | 96.52 mm |
| May | 10.2 °C | 22.7 °C | 124.46 mm |
| June | 15.6 °C | 27.6 °C | 113.54 mm |
| July | 17.4 °C | 29.2 °C | 99.31 mm |
| August | 16.2 °C | 28.3 °C | 90.68 mm |
| September | 11.6 °C | 25.2 °C | 90.93 mm |
| October | 5.1 °C | 18.2 °C | 78.49 mm |
| November | -1.2 °C | 9.7 °C | 68.83 mm |
| December | -6.5 °C | 2.7 °C | 52.83 mm |
| Annual | 4.3 °C | 16 °C | 981.96 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 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 |