Carpenter, Iowa has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.4 °F (low) to 54.8 °F (high). Annual precipitation averages 36.6 Inches. 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 | 6.5 °F | 23.3 °F | 1.03 in. |
| February | 10.5 °F | 27.8 °F | 1.12 in. |
| March | 22.7 °F | 40.2 °F | 1.95 in. |
| April | 34.7 °F | 55.8 °F | 3.86 in. |
| May | 47.1 °F | 68.2 °F | 5.04 in. |
| June | 57.9 °F | 78.0 °F | 5.34 in. |
| July | 61.2 °F | 81.2 °F | 4.74 in. |
| August | 58.6 °F | 78.9 °F | 4.11 in. |
| September | 49.9 °F | 72.7 °F | 3.5 in. |
| October | 37.3 °F | 59.1 °F | 2.7 in. |
| November | 25.1 °F | 42.8 °F | 1.77 in. |
| December | 13.6 °F | 29.0 °F | 1.39 in. |
| Annual | 35.4 °F | 54.8 °F | 36.55 in. |
| 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 : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |