Hardy, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 2.6 °C (low) to 13.7 °C (high). Annual precipitation averages 880.4 Millimeters. Hardy 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 | -13.2 °C | -3.7 °C | 21.34 mm |
| February | -10.9 °C | -1.2 °C | 26.92 mm |
| March | -4.2 °C | 6.1 °C | 52.32 mm |
| April | 2.1 °C | 14.4 °C | 95.25 mm |
| May | 9.1 °C | 21 °C | 124.46 mm |
| June | 15.1 °C | 26.5 °C | 135.64 mm |
| July | 17 °C | 28.2 °C | 104.39 mm |
| August | 15.3 °C | 26.9 °C | 107.44 mm |
| September | 10.4 °C | 23.6 °C | 77.72 mm |
| October | 3.4 °C | 16.3 °C | 60.71 mm |
| November | -3.4 °C | 7.1 °C | 41.4 mm |
| December | -9.7 °C | -0.7 °C | 32.77 mm |
| Annual | 2.6 °C | 13.7 °C | 880.36 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |