Wellman, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.8 °F (low) to 60.2 °F (high). Annual precipitation averages 37.6 Inches. Wellman 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 | 13.2 °F | 30.1 °F | 1.25 in. |
| February | 16.8 °F | 34.7 °F | 1.49 in. |
| March | 27.7 °F | 47.8 °F | 2.26 in. |
| April | 38.8 °F | 61.7 °F | 3.69 in. |
| May | 51.0 °F | 72.4 °F | 4.96 in. |
| June | 61.2 °F | 81.7 °F | 5.17 in. |
| July | 64.7 °F | 85.1 °F | 4.18 in. |
| August | 62.0 °F | 83.3 °F | 4.36 in. |
| September | 53.1 °F | 77.2 °F | 3.49 in. |
| October | 41.1 °F | 64.1 °F | 2.93 in. |
| November | 29.4 °F | 48.5 °F | 2.17 in. |
| December | 19.1 °F | 35.4 °F | 1.67 in. |
| Annual | 39.8 °F | 60.2 °F | 37.62 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 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |