Kempton, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.9 °C (low) to 16.3 °C (high). Annual precipitation averages 973.1 Millimeters. Kempton 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 | -8.7 °C | 0.3 °C | 54.86 mm |
| February | -6.9 °C | 2.9 °C | 47.24 mm |
| March | -1.6 °C | 9.8 °C | 64.26 mm |
| April | 4.2 °C | 16.7 °C | 94.23 mm |
| May | 10.6 °C | 22.8 °C | 114.55 mm |
| June | 15.9 °C | 27.8 °C | 114.3 mm |
| July | 17.7 °C | 29.3 °C | 108.97 mm |
| August | 16.4 °C | 28.3 °C | 93.47 mm |
| September | 11.7 °C | 25.6 °C | 79.25 mm |
| October | 5.7 °C | 18.4 °C | 81.53 mm |
| November | -0.2 °C | 10.3 °C | 67.82 mm |
| December | -5.7 °C | 3.2 °C | 52.58 mm |
| Annual | 4.9 °C | 16.3 °C | 973.06 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 |