Haverhill, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.3 °C (low) to 14.5 °C (high). Annual precipitation averages 932.7 Millimeters. Haverhill 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 | -11.9 °C | -2.4 °C | 25.15 mm |
| February | -9.8 °C | 0.2 °C | 29.72 mm |
| March | -3.6 °C | 7.4 °C | 52.07 mm |
| April | 2.7 °C | 15.3 °C | 98.04 mm |
| May | 9.7 °C | 21.4 °C | 126.24 mm |
| June | 15.6 °C | 26.8 °C | 138.94 mm |
| July | 17.4 °C | 28.6 °C | 110.24 mm |
| August | 15.9 °C | 27.4 °C | 109.98 mm |
| September | 11 °C | 24.2 °C | 88.65 mm |
| October | 4.2 °C | 16.8 °C | 67.06 mm |
| November | -2.6 °C | 8 °C | 50.29 mm |
| December | -8.5 °C | 0.7 °C | 36.32 mm |
| Annual | 3.3 °C | 14.5 °C | 932.7 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 | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |