Towanda, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.2 °C (low) to 16.4 °C (high). Annual precipitation averages 971.3 Millimeters. Towanda is located in USDA Plant Hardiness Zone 6a. 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 | 58.17 mm |
| February | -6.8 °C | 3 °C | 48.26 mm |
| March | -1.7 °C | 9.6 °C | 66.8 mm |
| April | 4.4 °C | 17 °C | 94.74 mm |
| May | 10.9 °C | 23.1 °C | 113.28 mm |
| June | 16.3 °C | 27.9 °C | 104.9 mm |
| July | 18 °C | 29.6 °C | 99.06 mm |
| August | 16.9 °C | 28.6 °C | 89.92 mm |
| September | 12.4 °C | 25.8 °C | 84.07 mm |
| October | 6.1 °C | 18.6 °C | 85.09 mm |
| November | -0.2 °C | 10.2 °C | 69.85 mm |
| December | -5.4 °C | 3.2 °C | 57.15 mm |
| Annual | 5.2 °C | 16.4 °C | 971.29 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 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 |