Yorktown, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.9 °F (low) to 61.5 °F (high). Annual precipitation averages 35 Inches. Yorktown 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 | 13.1 °F | 32.5 °F | 0.85 in. |
| February | 17.4 °F | 37.9 °F | 1.05 in. |
| March | 28.2 °F | 50.7 °F | 1.89 in. |
| April | 38.4 °F | 62.6 °F | 3.19 in. |
| May | 50.7 °F | 72.6 °F | 5.66 in. |
| June | 61.2 °F | 81.7 °F | 5.38 in. |
| July | 65.2 °F | 85.3 °F | 4.29 in. |
| August | 62.5 °F | 83.9 °F | 3.64 in. |
| September | 53.2 °F | 77.9 °F | 3.04 in. |
| October | 41.0 °F | 65.8 °F | 2.81 in. |
| November | 28.7 °F | 50.1 °F | 1.96 in. |
| December | 18.7 °F | 37.5 °F | 1.19 in. |
| Annual | 39.9 °F | 61.5 °F | 34.95 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 |