Machesney Park, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.6 °C (low) to 14.4 °C (high). Annual precipitation averages 957.8 Millimeters. Machesney Park 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 | -10.9 °C | -2 °C | 40.13 mm |
| February | -9.1 °C | 0.3 °C | 41.66 mm |
| March | -3.3 °C | 7.2 °C | 52.83 mm |
| April | 2.7 °C | 14.6 °C | 94.74 mm |
| May | 9.2 °C | 21.1 °C | 112.52 mm |
| June | 14.7 °C | 26.4 °C | 139.95 mm |
| July | 16.8 °C | 28.3 °C | 96.01 mm |
| August | 15.8 °C | 27.4 °C | 104.9 mm |
| September | 11.2 °C | 23.8 °C | 91.19 mm |
| October | 4.7 °C | 16.6 °C | 72.9 mm |
| November | -1.6 °C | 8.1 °C | 59.94 mm |
| December | -7.3 °C | 1.1 °C | 51.05 mm |
| Annual | 3.6 °C | 14.4 °C | 957.82 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |