Clarence, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38.2 °F (low) to 58.6 °F (high). Annual precipitation averages 38.3 Inches. Clarence 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 | 11.4 °F | 28.4 °F | 1.4 in. |
| February | 15.2 °F | 32.9 °F | 1.61 in. |
| March | 26.3 °F | 46.1 °F | 2.36 in. |
| April | 37.3 °F | 60.1 °F | 3.72 in. |
| May | 49.2 °F | 71.1 °F | 4.52 in. |
| June | 59.4 °F | 80.4 °F | 5.18 in. |
| July | 62.6 °F | 83.3 °F | 4.31 in. |
| August | 60.2 °F | 81.7 °F | 4.37 in. |
| September | 51.5 °F | 75.8 °F | 3.7 in. |
| October | 39.7 °F | 62.7 °F | 3.06 in. |
| November | 28.1 °F | 47.3 °F | 2.26 in. |
| December | 17.7 °F | 33.9 °F | 1.76 in. |
| Annual | 38.2 °F | 58.6 °F | 38.25 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 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 |