Hanlontown, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 2 °C (low) to 12.9 °C (high). Annual precipitation averages 902 Millimeters. Hanlontown 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 | -14.1 °C | -4.7 °C | 24.13 mm |
| February | -11.8 °C | -2.2 °C | 25.91 mm |
| March | -4.9 °C | 4.8 °C | 49.53 mm |
| April | 1.6 °C | 13.5 °C | 96.27 mm |
| May | 8.5 °C | 20.3 °C | 128.27 mm |
| June | 14.5 °C | 25.8 °C | 136.91 mm |
| July | 16.4 °C | 27.6 °C | 115.82 mm |
| August | 14.9 °C | 26.3 °C | 100.84 mm |
| September | 10 °C | 22.9 °C | 86.11 mm |
| October | 3.1 °C | 15.4 °C | 62.99 mm |
| November | -3.7 °C | 6.2 °C | 42.16 mm |
| December | -10.2 °C | -1.5 °C | 33.02 mm |
| Annual | 2 °C | 12.9 °C | 901.96 mm |
| 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 : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |