Iola, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34 °F (low) to 54.4 °F (high). Annual precipitation averages 33.5 Inches. Iola is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.4 °F | 24.5 °F | 1.26 in. |
| February | 9.5 °F | 28.6 °F | 1.11 in. |
| March | 20.3 °F | 40.3 °F | 1.82 in. |
| April | 32.3 °F | 54.4 °F | 3.28 in. |
| May | 44.6 °F | 67.2 °F | 3.96 in. |
| June | 54.5 °F | 76.6 °F | 4.62 in. |
| July | 58.5 °F | 81.0 °F | 3.76 in. |
| August | 56.6 °F | 78.8 °F | 3.8 in. |
| September | 48.2 °F | 71.2 °F | 3.5 in. |
| October | 36.4 °F | 57.5 °F | 2.81 in. |
| November | 25.5 °F | 42.6 °F | 1.91 in. |
| December | 14.3 °F | 29.6 °F | 1.63 in. |
| Annual | 34 °F | 54.4 °F | 33.46 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |