Andover, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.7 °C (low) to 14.9 °C (high). Annual precipitation averages 957.6 Millimeters. Andover is located in USDA Plant Hardiness Zone 5a. 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 | -11.1 °C | -1.7 °C | 38.35 mm |
| February | -9.1 °C | 0.8 °C | 43.43 mm |
| March | -3 °C | 7.8 °C | 60.96 mm |
| April | 3.1 °C | 15.4 °C | 93.22 mm |
| May | 9.6 °C | 21.8 °C | 114.3 mm |
| June | 15.2 °C | 27 °C | 130.3 mm |
| July | 17.1 °C | 28.6 °C | 107.44 mm |
| August | 15.8 °C | 27.6 °C | 99.82 mm |
| September | 11.2 °C | 24.3 °C | 92.71 mm |
| October | 4.7 °C | 17.1 °C | 71.37 mm |
| November | -1.7 °C | 8.6 °C | 57.66 mm |
| December | -7.5 °C | 1.4 °C | 48.01 mm |
| Annual | 3.7 °C | 14.9 °C | 957.57 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 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |