Summit 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 10.3 °C (high). Annual precipitation averages 845.6 Millimeters. Summit 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 | -15.8 °C | -6.2 °C | 30.23 mm |
| February | -15.1 °C | -3.6 °C | 26.92 mm |
| March | -9.6 °C | 2.8 °C | 40.89 mm |
| April | -2.2 °C | 10 °C | 72.14 mm |
| May | 5.1 °C | 17.9 °C | 98.81 mm |
| June | 10.6 °C | 22.7 °C | 118.11 mm |
| July | 12.8 °C | 25 °C | 98.3 mm |
| August | 11.8 °C | 23.8 °C | 85.09 mm |
| September | 7.7 °C | 19.6 °C | 104.39 mm |
| October | 1.3 °C | 11.7 °C | 82.55 mm |
| November | -4.9 °C | 3.4 °C | 47.75 mm |
| December | -11.9 °C | -3.6 °C | 40.39 mm |
| Annual | -0.9 °C | 10.3 °C | 845.57 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 |