Morning Sun, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.9 °C (low) to 15.9 °C (high). Annual precipitation averages 951.2 Millimeters. Morning Sun is located in USDA Plant Hardiness Zone 5b. 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 | -9.6 °C | -0.5 °C | 36.07 mm |
| February | -7.4 °C | 2.2 °C | 44.45 mm |
| March | -1.8 °C | 9.3 °C | 62.74 mm |
| April | 4.3 °C | 16.7 °C | 92.46 mm |
| May | 10.9 °C | 22.5 °C | 127 mm |
| June | 16.3 °C | 27.6 °C | 124.71 mm |
| July | 18.3 °C | 29.3 °C | 99.06 mm |
| August | 17 °C | 28.5 °C | 101.85 mm |
| September | 12.2 °C | 25.1 °C | 88.39 mm |
| October | 5.8 °C | 18.1 °C | 71.37 mm |
| November | -0.7 °C | 9.4 °C | 57.15 mm |
| December | -6.3 °C | 2.5 °C | 45.97 mm |
| Annual | 4.9 °C | 15.9 °C | 951.22 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |