Dunlap, 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 60.3 °F (high). Annual precipitation averages 32.8 Inches. Dunlap 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 | 11.0 °F | 30.1 °F | 0.72 in. |
| February | 15.0 °F | 35.1 °F | 0.93 in. |
| March | 26.3 °F | 48.5 °F | 1.78 in. |
| April | 37.0 °F | 61.7 °F | 3.44 in. |
| May | 49.4 °F | 72.4 °F | 4.69 in. |
| June | 60.2 °F | 82.3 °F | 4.9 in. |
| July | 64.0 °F | 85.4 °F | 3.81 in. |
| August | 61.1 °F | 83.3 °F | 4.21 in. |
| September | 51.9 °F | 77.3 °F | 3.26 in. |
| October | 39.2 °F | 64.5 °F | 2.43 in. |
| November | 26.4 °F | 48.4 °F | 1.41 in. |
| December | 16.4 °F | 35.0 °F | 1.21 in. |
| Annual | 38.2 °F | 60.3 °F | 32.79 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |