Dow City, 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 15.4 °C (high). Annual precipitation averages 836.2 Millimeters. Dow City 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 | -11.8 °C | -1.4 °C | 18.54 mm |
| February | -9.6 °C | 1.4 °C | 23.88 mm |
| March | -3.4 °C | 8.7 °C | 45.72 mm |
| April | 2.4 °C | 16.2 °C | 87.12 mm |
| May | 9.3 °C | 22.1 °C | 118.62 mm |
| June | 15.3 °C | 27.6 °C | 124.21 mm |
| July | 17.4 °C | 29.3 °C | 98.55 mm |
| August | 15.8 °C | 28.1 °C | 108.71 mm |
| September | 10.7 °C | 24.9 °C | 82.04 mm |
| October | 3.8 °C | 17.8 °C | 62.23 mm |
| November | -3.3 °C | 8.8 °C | 36.07 mm |
| December | -8.9 °C | 1.4 °C | 30.48 mm |
| Annual | 3.1 °C | 15.4 °C | 836.17 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 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 |