Tomahawk, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.9 °C (low) to 10.8 °C (high). Annual precipitation averages 827.8 Millimeters. Tomahawk is located in USDA Plant Hardiness Zone 4a. 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 | -16.4 °C | -5.7 °C | 31.24 mm |
| February | -15.7 °C | -3.1 °C | 26.92 mm |
| March | -9.5 °C | 3.2 °C | 42.16 mm |
| April | -2.1 °C | 10.6 °C | 72.14 mm |
| May | 5.3 °C | 18.3 °C | 91.19 mm |
| June | 11 °C | 23.2 °C | 110.49 mm |
| July | 13.1 °C | 25.4 °C | 96.77 mm |
| August | 11.9 °C | 24.2 °C | 91.95 mm |
| September | 7.6 °C | 20 °C | 97.54 mm |
| October | 1.2 °C | 12.3 °C | 80.77 mm |
| November | -5.1 °C | 3.9 °C | 48.77 mm |
| December | -12 °C | -3 °C | 37.85 mm |
| Annual | -0.9 °C | 10.8 °C | 827.79 mm |
| 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 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |