Franklin Park, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.5 °C (low) to 15.2 °C (high). Annual precipitation averages 981.5 Millimeters. Franklin Park 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.2 °C | -0.2 °C | 54.1 mm |
| February | -6.7 °C | 1.9 °C | 52.83 mm |
| March | -1.7 °C | 7.8 °C | 58.67 mm |
| April | 4.1 °C | 14.7 °C | 99.57 mm |
| May | 10.1 °C | 20.9 °C | 118.11 mm |
| June | 15.8 °C | 26.6 °C | 111.51 mm |
| July | 18.7 °C | 29 °C | 93.73 mm |
| August | 17.9 °C | 27.9 °C | 101.09 mm |
| September | 13.5 °C | 24.3 °C | 83.82 mm |
| October | 6.8 °C | 17.1 °C | 85.85 mm |
| November | 0.5 °C | 9.3 °C | 64.77 mm |
| December | -5 °C | 2.8 °C | 57.4 mm |
| Annual | 5.5 °C | 15.2 °C | 981.45 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |