Randalia, Iowa has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36 °F (low) to 56.1 °F (high). Annual precipitation averages 38.5 Inches. Randalia is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.8 °F | 25.1 °F | 1.17 in. |
| February | 11.5 °F | 29.4 °F | 1.19 in. |
| March | 23.7 °F | 42.7 °F | 2.03 in. |
| April | 35.2 °F | 57.2 °F | 3.99 in. |
| May | 47.2 °F | 69.2 °F | 4.87 in. |
| June | 58.1 °F | 78.8 °F | 5.89 in. |
| July | 61.3 °F | 81.8 °F | 5.07 in. |
| August | 58.6 °F | 79.6 °F | 4.09 in. |
| September | 50.2 °F | 73.6 °F | 3.71 in. |
| October | 37.8 °F | 60.5 °F | 2.84 in. |
| November | 25.8 °F | 44.2 °F | 2.02 in. |
| December | 14.7 °F | 30.9 °F | 1.59 in. |
| Annual | 36 °F | 56.1 °F | 38.46 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |