Weldon, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.3 °C (low) to 15.7 °C (high). Annual precipitation averages 964.4 Millimeters. Weldon 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 | -10.6 °C | -0.3 °C | 24.64 mm |
| February | -8.3 °C | 2.3 °C | 34.29 mm |
| March | -2.4 °C | 9.4 °C | 56.13 mm |
| April | 3.7 °C | 16.2 °C | 100.58 mm |
| May | 10.2 °C | 21.7 °C | 138.43 mm |
| June | 15.8 °C | 26.9 °C | 129.54 mm |
| July | 18.2 °C | 29.4 °C | 111.76 mm |
| August | 16.8 °C | 28.5 °C | 109.98 mm |
| September | 11.7 °C | 24.5 °C | 96.77 mm |
| October | 5 °C | 17.7 °C | 72.39 mm |
| November | -1.7 °C | 9.4 °C | 52.58 mm |
| December | -7.4 °C | 2.4 °C | 37.34 mm |
| Annual | 4.3 °C | 15.7 °C | 964.43 mm |
| 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 : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |