Superior, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 35.3 °F (low) to 55.2 °F (high). Annual precipitation averages 31 Inches. Superior is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.6 °F | 23.5 °F | 0.78 in. |
| February | 10.1 °F | 27.7 °F | 0.83 in. |
| March | 22.2 °F | 40.4 °F | 1.68 in. |
| April | 34.2 °F | 56.0 °F | 3.29 in. |
| May | 46.9 °F | 68.4 °F | 4.5 in. |
| June | 57.8 °F | 78.5 °F | 4.83 in. |
| July | 61.8 °F | 82.7 °F | 3.67 in. |
| August | 58.8 °F | 79.8 °F | 3.67 in. |
| September | 50.5 °F | 74.1 °F | 3.13 in. |
| October | 37.1 °F | 59.5 °F | 2.35 in. |
| November | 24.6 °F | 42.9 °F | 1.31 in. |
| December | 12.4 °F | 28.6 °F | 0.95 in. |
| Annual | 35.3 °F | 55.2 °F | 30.99 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |