Hammond, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6 °C (low) to 17.1 °C (high). Annual precipitation averages 1016.5 Millimeters. Hammond 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 | -7.3 °C | 1.5 °C | 58.67 mm |
| February | -5.7 °C | 4.2 °C | 51.56 mm |
| March | -0.5 °C | 10.4 °C | 69.34 mm |
| April | 5.4 °C | 17.7 °C | 113.28 mm |
| May | 11.8 °C | 23.5 °C | 117.35 mm |
| June | 16.8 °C | 28.3 °C | 119.38 mm |
| July | 18.4 °C | 29.7 °C | 100.33 mm |
| August | 17.2 °C | 28.9 °C | 74.17 mm |
| September | 12.9 °C | 26.4 °C | 80.52 mm |
| October | 6.4 °C | 19.3 °C | 85.85 mm |
| November | 0.5 °C | 10.9 °C | 83.57 mm |
| December | -4 °C | 4.3 °C | 62.48 mm |
| Annual | 6 °C | 17.1 °C | 1016.5 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 |