Schleswig, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37.9 °F (low) to 57.7 °F (high). Annual precipitation averages 32.5 Inches. Schleswig 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 | 9.8 °F | 27.3 °F | 0.66 in. |
| February | 13.9 °F | 32.2 °F | 0.94 in. |
| March | 25.4 °F | 45.5 °F | 1.78 in. |
| April | 36.8 °F | 58.9 °F | 3.29 in. |
| May | 49.2 °F | 70.0 °F | 4.6 in. |
| June | 60.0 °F | 79.9 °F | 4.75 in. |
| July | 63.7 °F | 82.9 °F | 3.85 in. |
| August | 60.9 °F | 80.8 °F | 4.52 in. |
| September | 52.1 °F | 74.9 °F | 3.26 in. |
| October | 39.9 °F | 62.0 °F | 2.28 in. |
| November | 26.6 °F | 45.8 °F | 1.32 in. |
| December | 15.9 °F | 32.4 °F | 1.22 in. |
| Annual | 37.9 °F | 57.7 °F | 32.47 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |