Doon, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 35.9 °F (low) to 57.6 °F (high). Annual precipitation averages 28.9 Inches. Doon is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.6 °F | 26.1 °F | 0.62 in. |
| February | 12.1 °F | 31.0 °F | 0.78 in. |
| March | 23.5 °F | 43.7 °F | 1.52 in. |
| April | 34.8 °F | 58.6 °F | 2.98 in. |
| May | 47.5 °F | 70.8 °F | 3.94 in. |
| June | 58.6 °F | 81.0 °F | 4.68 in. |
| July | 62.1 °F | 84.5 °F | 3.33 in. |
| August | 59.5 °F | 82.2 °F | 3.29 in. |
| September | 50.1 °F | 75.6 °F | 3.02 in. |
| October | 37.2 °F | 61.8 °F | 2.43 in. |
| November | 24.2 °F | 44.7 °F | 1.37 in. |
| December | 13.2 °F | 30.8 °F | 0.9 in. |
| Annual | 35.9 °F | 57.6 °F | 28.86 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |