Gillett, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.4 °F (low) to 54.6 °F (high). Annual precipitation averages 33.8 Inches. Gillett 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 | 7.0 °F | 25.1 °F | 1.4 in. |
| February | 8.5 °F | 28.9 °F | 1.19 in. |
| March | 19.3 °F | 40.4 °F | 1.81 in. |
| April | 31.5 °F | 54.4 °F | 3.31 in. |
| May | 43.6 °F | 67.4 °F | 3.71 in. |
| June | 53.6 °F | 76.5 °F | 4.7 in. |
| July | 57.8 °F | 80.9 °F | 3.79 in. |
| August | 55.9 °F | 78.9 °F | 3.65 in. |
| September | 47.6 °F | 71.6 °F | 3.59 in. |
| October | 36.2 °F | 57.7 °F | 3.04 in. |
| November | 25.8 °F | 43.0 °F | 1.87 in. |
| December | 14.3 °F | 30.0 °F | 1.72 in. |
| Annual | 33.4 °F | 54.6 °F | 33.78 in. |
| 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 : -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 |