Holstein, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.1 °C (low) to 14.2 °C (high). Annual precipitation averages 823.7 Millimeters. Holstein 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 | -12.6 °C | -2.8 °C | 20.57 mm |
| February | -10.2 °C | -0.2 °C | 24.89 mm |
| March | -3.8 °C | 7.4 °C | 46.48 mm |
| April | 2.5 °C | 15.1 °C | 88.39 mm |
| May | 9.4 °C | 21.3 °C | 113.03 mm |
| June | 15.6 °C | 26.7 °C | 131.06 mm |
| July | 17.6 °C | 28.3 °C | 91.69 mm |
| August | 15.9 °C | 27.1 °C | 108.71 mm |
| September | 11.1 °C | 23.9 °C | 75.44 mm |
| October | 4.1 °C | 16.6 °C | 58.42 mm |
| November | -3.2 °C | 7.5 °C | 36.58 mm |
| December | -9.2 °C | -0.1 °C | 28.45 mm |
| Annual | 3.1 °C | 14.2 °C | 823.71 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 |