Carpenter, Iowa has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.9 °C (low) to 12.7 °C (high). Annual precipitation averages 928.4 Millimeters. Carpenter 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 | -14.2 °C | -4.8 °C | 26.16 mm |
| February | -11.9 °C | -2.3 °C | 28.45 mm |
| March | -5.2 °C | 4.6 °C | 49.53 mm |
| April | 1.5 °C | 13.2 °C | 98.04 mm |
| May | 8.4 °C | 20.1 °C | 128.02 mm |
| June | 14.4 °C | 25.6 °C | 135.64 mm |
| July | 16.2 °C | 27.3 °C | 120.4 mm |
| August | 14.8 °C | 26.1 °C | 104.39 mm |
| September | 9.9 °C | 22.6 °C | 88.9 mm |
| October | 2.9 °C | 15.1 °C | 68.58 mm |
| November | -3.8 °C | 6 °C | 44.96 mm |
| December | -10.2 °C | -1.7 °C | 35.31 mm |
| Annual | 1.9 °C | 12.7 °C | 928.38 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |