Harris, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.9 °C (low) to 13 °C (high). Annual precipitation averages 785.1 Millimeters. Harris 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 | -14.3 °C | -4.8 °C | 19.3 mm |
| February | -12.1 °C | -2.3 °C | 23.37 mm |
| March | -5.6 °C | 4.8 °C | 40.39 mm |
| April | 1.2 °C | 13.3 °C | 83.31 mm |
| May | 8.4 °C | 20.5 °C | 110.49 mm |
| June | 14.7 °C | 26.2 °C | 123.7 mm |
| July | 16.7 °C | 28.4 °C | 91.19 mm |
| August | 15.3 °C | 26.8 °C | 91.44 mm |
| September | 10.4 °C | 23.2 °C | 79.5 mm |
| October | 3.1 °C | 15.4 °C | 60.45 mm |
| November | -4.3 °C | 5.9 °C | 35.31 mm |
| December | -10.9 °C | -1.9 °C | 26.67 mm |
| Annual | 1.9 °C | 13 °C | 785.12 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 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |