Magnolia, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.1 °C (low) to 15.6 °C (high). Annual precipitation averages 838.5 Millimeters. Magnolia is located in USDA Plant Hardiness Zone 5b. 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 | -11.1 °C | -0.9 °C | 18.29 mm |
| February | -8.8 °C | 2 °C | 23.62 mm |
| March | -2.8 °C | 9.2 °C | 46.23 mm |
| April | 3.4 °C | 16.3 °C | 85.6 mm |
| May | 10.2 °C | 22.2 °C | 121.16 mm |
| June | 16.1 °C | 27.7 °C | 128.02 mm |
| July | 18.2 °C | 29.6 °C | 95.25 mm |
| August | 16.9 °C | 28.3 °C | 105.66 mm |
| September | 11.8 °C | 24.8 °C | 84.07 mm |
| October | 4.9 °C | 17.8 °C | 62.48 mm |
| November | -2.2 °C | 8.9 °C | 36.07 mm |
| December | -8 °C | 1.6 °C | 32 mm |
| Annual | 4.1 °C | 15.6 °C | 838.45 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 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |