Harvey, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.8 °C (low) to 15.9 °C (high). Annual precipitation averages 927.4 Millimeters. Harvey is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10 °C | -0.4 °C | 27.69 mm |
| February | -8.2 °C | 2.2 °C | 36.07 mm |
| March | -2 °C | 9.4 °C | 52.83 mm |
| April | 4.4 °C | 16.5 °C | 97.54 mm |
| May | 11.1 °C | 22.3 °C | 132.84 mm |
| June | 16.8 °C | 27.8 °C | 124.71 mm |
| July | 18.5 °C | 30 °C | 108.2 mm |
| August | 17.4 °C | 28.8 °C | 104.65 mm |
| September | 12.3 °C | 24.8 °C | 90.17 mm |
| October | 5.7 °C | 18.3 °C | 65.79 mm |
| November | -1.1 °C | 9.1 °C | 51.56 mm |
| December | -6.9 °C | 2.4 °C | 35.31 mm |
| Annual | 4.8 °C | 15.9 °C | 927.36 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |