Havelock, 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 13.9 °C (high). Annual precipitation averages 845.6 Millimeters. Havelock 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 | -13.3 °C | -3.6 °C | 22.35 mm |
| February | -10.9 °C | -1.2 °C | 25.65 mm |
| March | -4.2 °C | 6.3 °C | 48.77 mm |
| April | 2.1 °C | 14.6 °C | 90.17 mm |
| May | 9.1 °C | 21.1 °C | 115.57 mm |
| June | 15.2 °C | 26.8 °C | 129.79 mm |
| July | 17 °C | 28.6 °C | 95.5 mm |
| August | 15.4 °C | 27.1 °C | 112.78 mm |
| September | 10.5 °C | 23.9 °C | 76.96 mm |
| October | 3.5 °C | 16.6 °C | 58.42 mm |
| November | -3.6 °C | 7.1 °C | 39.37 mm |
| December | -9.8 °C | -0.7 °C | 30.23 mm |
| Annual | 2.6 °C | 13.9 °C | 845.56 mm |
| 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 : -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 |