Ainsworth, 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 16 °C (high). Annual precipitation averages 956.6 Millimeters. Ainsworth is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.8 °C | -0.5 °C | 34.29 mm |
| February | -7.8 °C | 2.1 °C | 40.13 mm |
| March | -1.9 °C | 9.2 °C | 59.94 mm |
| April | 4.3 °C | 16.8 °C | 93.98 mm |
| May | 10.9 °C | 22.7 °C | 126.24 mm |
| June | 16.4 °C | 27.8 °C | 128.02 mm |
| July | 18.3 °C | 29.7 °C | 105.41 mm |
| August | 16.9 °C | 28.7 °C | 106.68 mm |
| September | 12 °C | 25.3 °C | 87.63 mm |
| October | 5.5 °C | 18.2 °C | 74.42 mm |
| November | -0.8 °C | 9.6 °C | 56.39 mm |
| December | -6.6 °C | 2.3 °C | 43.43 mm |
| Annual | 4.8 °C | 16 °C | 956.56 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 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 |