Superior, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.7 °F (low) to 49.4 °F (high). Annual precipitation averages 29.7 Inches. 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 | 5.0 °F | 22.0 °F | 0.99 in. |
| February | 7.9 °F | 26.4 °F | 0.93 in. |
| March | 18.8 °F | 35.8 °F | 1.29 in. |
| April | 30.9 °F | 45.9 °F | 2.53 in. |
| May | 39.9 °F | 57.4 °F | 3.05 in. |
| June | 49.0 °F | 67.2 °F | 4.2 in. |
| July | 57.3 °F | 75.7 °F | 3.76 in. |
| August | 57.3 °F | 75.1 °F | 3.57 in. |
| September | 49.1 °F | 66.7 °F | 3.24 in. |
| October | 38.1 °F | 53.5 °F | 2.97 in. |
| November | 26.0 °F | 40.0 °F | 1.85 in. |
| December | 12.9 °F | 27.0 °F | 1.31 in. |
| Annual | 32.7 °F | 49.4 °F | 29.69 in. |
| 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 : -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 |