Stanwood, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38 °F (low) to 58.4 °F (high). Annual precipitation averages 38.3 Inches. Stanwood 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 | 11.2 °F | 28.1 °F | 1.37 in. |
| February | 14.9 °F | 32.7 °F | 1.58 in. |
| March | 26.1 °F | 45.8 °F | 2.33 in. |
| April | 37.1 °F | 59.8 °F | 3.71 in. |
| May | 49.0 °F | 70.8 °F | 4.55 in. |
| June | 59.2 °F | 80.1 °F | 5.23 in. |
| July | 62.5 °F | 83.0 °F | 4.34 in. |
| August | 60.0 °F | 81.4 °F | 4.39 in. |
| September | 51.4 °F | 75.5 °F | 3.7 in. |
| October | 39.5 °F | 62.4 °F | 3.06 in. |
| November | 27.9 °F | 47.0 °F | 2.25 in. |
| December | 17.5 °F | 33.7 °F | 1.75 in. |
| Annual | 38 °F | 58.4 °F | 38.26 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |