Kirkman, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.4 °C (low) to 15.3 °C (high). Annual precipitation averages 869.2 Millimeters. Kirkman 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 | -11.7 °C | -1.4 °C | 21.84 mm |
| February | -9.4 °C | 1.3 °C | 26.92 mm |
| March | -3.3 °C | 8.8 °C | 49.02 mm |
| April | 2.7 °C | 16.2 °C | 90.93 mm |
| May | 9.7 °C | 22.1 °C | 122.94 mm |
| June | 15.4 °C | 27.3 °C | 126.24 mm |
| July | 17.6 °C | 29.1 °C | 95.5 mm |
| August | 16.1 °C | 28.1 °C | 107.7 mm |
| September | 10.9 °C | 24.7 °C | 91.19 mm |
| October | 4.2 °C | 17.8 °C | 67.31 mm |
| November | -2.9 °C | 8.6 °C | 36.83 mm |
| December | -8.5 °C | 1.4 °C | 32.77 mm |
| Annual | 3.4 °C | 15.3 °C | 869.19 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 | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |