Gresham, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.6 °C (low) to 12.1 °C (high). Annual precipitation averages 839.5 Millimeters. Gresham is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.3 °C | -4.4 °C | 30.48 mm |
| February | -13.4 °C | -2.1 °C | 27.69 mm |
| March | -7.3 °C | 4.4 °C | 44.45 mm |
| April | -0.3 °C | 12.2 °C | 78.23 mm |
| May | 6.3 °C | 19.3 °C | 95.76 mm |
| June | 11.9 °C | 24.4 °C | 113.54 mm |
| July | 14.2 °C | 26.7 °C | 98.81 mm |
| August | 13.1 °C | 25.6 °C | 92.46 mm |
| September | 8.6 °C | 21.3 °C | 92.71 mm |
| October | 2.1 °C | 13.8 °C | 76.71 mm |
| November | -3.8 °C | 5.6 °C | 48.26 mm |
| December | -10.3 °C | -1.6 °C | 40.39 mm |
| Annual | 0.6 °C | 12.1 °C | 839.49 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |