Post Lake, 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 837.5 Millimeters. 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 | -15.9 °C | -5.7 °C | 30.48 mm |
| February | -15 °C | -3.1 °C | 27.43 mm |
| March | -9.3 °C | 3.3 °C | 41.91 mm |
| April | -2.1 °C | 10.6 °C | 72.9 mm |
| May | 4.9 °C | 18.3 °C | 95.76 mm |
| June | 10.6 °C | 23.3 °C | 114.81 mm |
| July | 12.7 °C | 25.5 °C | 99.57 mm |
| August | 11.7 °C | 24.3 °C | 84.84 mm |
| September | 7.4 °C | 20 °C | 99.57 mm |
| October | 1.1 °C | 12.2 °C | 82.04 mm |
| November | -5.1 °C | 3.9 °C | 48.26 mm |
| December | -11.9 °C | -3 °C | 39.88 mm |
| Annual | -0.9 °C | 10.8 °C | 837.45 mm |
| 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 : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |