Hull, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 2.1 °C (low) to 14 °C (high). Annual precipitation averages 744.7 Millimeters. Hull 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 | -13.7 °C | -3.4 °C | 17.02 mm |
| February | -11.2 °C | -0.7 °C | 20.57 mm |
| March | -4.9 °C | 6.4 °C | 40.89 mm |
| April | 1.4 °C | 14.7 °C | 76.96 mm |
| May | 8.5 °C | 21.5 °C | 101.85 mm |
| June | 14.7 °C | 27 °C | 117.09 mm |
| July | 16.6 °C | 28.7 °C | 85.6 mm |
| August | 15.2 °C | 27.5 °C | 85.6 mm |
| September | 10.1 °C | 24 °C | 78.49 mm |
| October | 3 °C | 16.6 °C | 61.47 mm |
| November | -4.3 °C | 6.9 °C | 35.05 mm |
| December | -10.5 °C | -0.8 °C | 24.13 mm |
| Annual | 2.1 °C | 14 °C | 744.72 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 |