Post Lake, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 30.4 °F (low) to 51.4 °F (high). Annual precipitation averages 33 Inches. Post Lake 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 | 3.3 °F | 21.8 °F | 1.2 in. |
| February | 5.0 °F | 26.4 °F | 1.08 in. |
| March | 15.3 °F | 37.9 °F | 1.65 in. |
| April | 28.2 °F | 51.0 °F | 2.87 in. |
| May | 40.8 °F | 65.0 °F | 3.77 in. |
| June | 51.0 °F | 73.9 °F | 4.52 in. |
| July | 54.9 °F | 77.9 °F | 3.92 in. |
| August | 53.0 °F | 75.8 °F | 3.34 in. |
| September | 45.3 °F | 68.0 °F | 3.92 in. |
| October | 34.0 °F | 54.0 °F | 3.23 in. |
| November | 22.9 °F | 39.0 °F | 1.9 in. |
| December | 10.6 °F | 26.6 °F | 1.57 in. |
| Annual | 30.4 °F | 51.4 °F | 32.97 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |