Towanda, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.4 °F (low) to 61.5 °F (high). Annual precipitation averages 38.2 Inches. 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 | 16.3 °F | 32.5 °F | 2.29 in. |
| February | 19.8 °F | 37.4 °F | 1.9 in. |
| March | 29.0 °F | 49.3 °F | 2.63 in. |
| April | 40.0 °F | 62.6 °F | 3.73 in. |
| May | 51.7 °F | 73.5 °F | 4.46 in. |
| June | 61.3 °F | 82.3 °F | 4.13 in. |
| July | 64.4 °F | 85.3 °F | 3.9 in. |
| August | 62.4 °F | 83.4 °F | 3.54 in. |
| September | 54.4 °F | 78.4 °F | 3.31 in. |
| October | 43.0 °F | 65.5 °F | 3.35 in. |
| November | 31.7 °F | 50.3 °F | 2.75 in. |
| December | 22.2 °F | 37.7 °F | 2.25 in. |
| Annual | 41.4 °F | 61.5 °F | 38.24 in. |
| 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 : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |