Carpentersville, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.9 °C (low) to 14.8 °C (high). Annual precipitation averages 1004.1 Millimeters. Carpentersville 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 | -9.9 °C | -1 °C | 49.78 mm |
| February | -8.4 °C | 1.3 °C | 48.01 mm |
| March | -3.1 °C | 7.8 °C | 56.39 mm |
| April | 2.6 °C | 14.7 °C | 96.52 mm |
| May | 8.7 °C | 21.1 °C | 129.79 mm |
| June | 14.2 °C | 26.6 °C | 123.19 mm |
| July | 17 °C | 28.8 °C | 102.11 mm |
| August | 16.2 °C | 27.5 °C | 106.17 mm |
| September | 11.7 °C | 23.7 °C | 90.17 mm |
| October | 5.2 °C | 16.6 °C | 83.31 mm |
| November | -0.9 °C | 8.7 °C | 64.01 mm |
| December | -6.6 °C | 1.8 °C | 54.61 mm |
| Annual | 3.9 °C | 14.8 °C | 1004.06 mm |
| 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 : -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 |