Stronghurst, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.3 °C (low) to 16.3 °C (high). Annual precipitation averages 979.2 Millimeters. Stronghurst is located in USDA Plant Hardiness Zone 5b. 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 | -9.2 °C | 0.2 °C | 41.4 mm |
| February | -7.1 °C | 2.8 °C | 46.99 mm |
| March | -1.3 °C | 9.7 °C | 62.74 mm |
| April | 4.7 °C | 16.9 °C | 97.28 mm |
| May | 11.3 °C | 22.7 °C | 130.3 mm |
| June | 16.7 °C | 27.8 °C | 121.92 mm |
| July | 18.5 °C | 29.6 °C | 102.62 mm |
| August | 17.3 °C | 28.7 °C | 93.98 mm |
| September | 12.7 °C | 25.4 °C | 94.23 mm |
| October | 6.2 °C | 18.4 °C | 75.69 mm |
| November | -0.3 °C | 10.1 °C | 63.5 mm |
| December | -5.8 °C | 3.1 °C | 48.51 mm |
| Annual | 5.3 °C | 16.3 °C | 979.16 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 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 |