Superior, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.4 °C (low) to 9.7 °C (high). Annual precipitation averages 754.1 Millimeters. Superior is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -15 °C | -5.6 °C | 25.15 mm |
| February | -13.4 °C | -3.1 °C | 23.62 mm |
| March | -7.3 °C | 2.1 °C | 32.77 mm |
| April | -0.6 °C | 7.7 °C | 64.26 mm |
| May | 4.4 °C | 14.1 °C | 77.47 mm |
| June | 9.4 °C | 19.6 °C | 106.68 mm |
| July | 14.1 °C | 24.3 °C | 95.5 mm |
| August | 14.1 °C | 23.9 °C | 90.68 mm |
| September | 9.5 °C | 19.3 °C | 82.3 mm |
| October | 3.4 °C | 11.9 °C | 75.44 mm |
| November | -3.3 °C | 4.4 °C | 46.99 mm |
| December | -10.6 °C | -2.8 °C | 33.27 mm |
| Annual | 0.4 °C | 9.7 °C | 754.13 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |