Pearl, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.3 °C (low) to 17.9 °C (high). Annual precipitation averages 1010.2 Millimeters. Pearl is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.1 °C | 2.6 °C | 54.61 mm |
| February | -5.1 °C | 5.4 °C | 51.31 mm |
| March | -0.2 °C | 11.7 °C | 73.15 mm |
| April | 5.7 °C | 18.6 °C | 106.17 mm |
| May | 12 °C | 23.8 °C | 120.65 mm |
| June | 17.1 °C | 28.7 °C | 118.62 mm |
| July | 19.1 °C | 30.6 °C | 101.35 mm |
| August | 17.7 °C | 29.9 °C | 86.87 mm |
| September | 12.9 °C | 26.6 °C | 87.12 mm |
| October | 6.7 °C | 19.8 °C | 76.45 mm |
| November | 0.8 °C | 11.9 °C | 76.45 mm |
| December | -4.3 °C | 5.2 °C | 57.4 mm |
| Annual | 6.3 °C | 17.9 °C | 1010.15 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°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 |