Welton, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.4 °F (low) to 59 °F (high). Annual precipitation averages 38.1 Inches. Welton 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 | 12.6 °F | 29.1 °F | 1.36 in. |
| February | 16.2 °F | 33.6 °F | 1.62 in. |
| March | 27.2 °F | 46.5 °F | 2.39 in. |
| April | 38.2 °F | 60.1 °F | 3.78 in. |
| May | 50.1 °F | 71.4 °F | 4.66 in. |
| June | 60.3 °F | 80.7 °F | 4.93 in. |
| July | 63.7 °F | 83.6 °F | 4.3 in. |
| August | 61.4 °F | 81.8 °F | 4.33 in. |
| September | 53.0 °F | 76.0 °F | 3.74 in. |
| October | 41.3 °F | 63.0 °F | 2.95 in. |
| November | 29.4 °F | 47.8 °F | 2.18 in. |
| December | 19.1 °F | 34.7 °F | 1.82 in. |
| Annual | 39.4 °F | 59 °F | 38.06 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 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |