Randolph, 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 62.4 °F (high). Annual precipitation averages 34.3 Inches. Randolph is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.1 °F | 33.2 °F | 0.81 in. |
| February | 17.1 °F | 38.4 °F | 1.12 in. |
| March | 28.2 °F | 51.4 °F | 1.79 in. |
| April | 38.7 °F | 63.6 °F | 3.41 in. |
| May | 51.4 °F | 73.7 °F | 5.54 in. |
| June | 62.0 °F | 83.1 °F | 5.25 in. |
| July | 65.7 °F | 86.5 °F | 3.96 in. |
| August | 62.7 °F | 85.0 °F | 3.51 in. |
| September | 53.2 °F | 78.7 °F | 3.21 in. |
| October | 40.7 °F | 66.5 °F | 2.83 in. |
| November | 28.0 °F | 50.5 °F | 1.6 in. |
| December | 18.2 °F | 37.9 °F | 1.29 in. |
| Annual | 39.9 °F | 62.4 °F | 34.32 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 |