Malvern, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.3 °C (low) to 16.6 °C (high). Annual precipitation averages 868.2 Millimeters. Malvern is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.6 °C | 0.4 °C | 20.32 mm |
| February | -8.4 °C | 3.2 °C | 25.65 mm |
| March | -2.3 °C | 10.4 °C | 45.72 mm |
| April | 3.6 °C | 17.3 °C | 86.11 mm |
| May | 10.6 °C | 22.9 °C | 139.45 mm |
| June | 16.4 °C | 28.3 °C | 133.1 mm |
| July | 18.7 °C | 30.1 °C | 99.06 mm |
| August | 17.1 °C | 29.3 °C | 94.23 mm |
| September | 11.8 °C | 25.8 °C | 83.06 mm |
| October | 4.8 °C | 18.8 °C | 69.6 mm |
| November | -2.2 °C | 9.9 °C | 40.13 mm |
| December | -7.7 °C | 2.9 °C | 31.75 mm |
| Annual | 4.3 °C | 16.6 °C | 868.18 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 |