Granton, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.4 °F (low) to 54 °F (high). Annual precipitation averages 33.9 Inches. Granton is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.1 °F | 23.4 °F | 1.1 in. |
| February | 7.8 °F | 28.2 °F | 1.03 in. |
| March | 19.5 °F | 40.4 °F | 1.7 in. |
| April | 32.5 °F | 54.7 °F | 3.16 in. |
| May | 44.8 °F | 67.3 °F | 4.01 in. |
| June | 54.8 °F | 76.4 °F | 4.93 in. |
| July | 58.5 °F | 80.5 °F | 3.89 in. |
| August | 56.5 °F | 78.4 °F | 4.12 in. |
| September | 48.1 °F | 70.9 °F | 3.8 in. |
| October | 36.3 °F | 57.4 °F | 2.86 in. |
| November | 24.8 °F | 41.8 °F | 1.83 in. |
| December | 12.5 °F | 28.7 °F | 1.43 in. |
| Annual | 33.4 °F | 54 °F | 33.86 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |