Holy Cross, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 36.6 °F (low) to 55.2 °F (high). Annual precipitation averages 39 Inches. Holy Cross 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 9.2 °F | 24.9 °F | 1.26 in. |
| February | 12.8 °F | 29.4 °F | 1.36 in. |
| March | 24.3 °F | 42.3 °F | 2.08 in. |
| April | 35.7 °F | 56.3 °F | 3.94 in. |
| May | 47.4 °F | 67.7 °F | 4.65 in. |
| June | 57.6 °F | 77.2 °F | 5.92 in. |
| July | 61.1 °F | 80.4 °F | 4.9 in. |
| August | 59.1 °F | 78.7 °F | 4.16 in. |
| September | 50.6 °F | 72.0 °F | 3.88 in. |
| October | 38.5 °F | 59.1 °F | 2.96 in. |
| November | 26.6 °F | 43.5 °F | 2.23 in. |
| December | 15.8 °F | 30.7 °F | 1.67 in. |
| Annual | 36.6 °F | 55.2 °F | 39.01 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°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 |