Dunbar, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 30.6 °F (low) to 52.5 °F (high). Annual precipitation averages 31.4 Inches. Dunbar is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.2 °F | 23.4 °F | 1.25 in. |
| February | 5.6 °F | 27.6 °F | 1.12 in. |
| March | 15.7 °F | 38.7 °F | 1.67 in. |
| April | 28.2 °F | 51.5 °F | 2.72 in. |
| May | 40.4 °F | 65.7 °F | 3.35 in. |
| June | 50.5 °F | 74.7 °F | 4.03 in. |
| July | 54.7 °F | 79.0 °F | 3.72 in. |
| August | 53.1 °F | 76.9 °F | 3.12 in. |
| September | 45.4 °F | 68.9 °F | 3.59 in. |
| October | 33.9 °F | 55.1 °F | 3.27 in. |
| November | 23.6 °F | 40.4 °F | 1.93 in. |
| December | 11.9 °F | 28.5 °F | 1.6 in. |
| Annual | 30.6 °F | 52.5 °F | 31.37 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |