Danbury, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37.1 °F (low) to 59.5 °F (high). Annual precipitation averages 31.7 Inches. Danbury 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 | 10.0 °F | 29.0 °F | 0.71 in. |
| February | 14.2 °F | 34.0 °F | 0.9 in. |
| March | 25.1 °F | 47.3 °F | 1.72 in. |
| April | 35.7 °F | 60.9 °F | 3.34 in. |
| May | 48.1 °F | 71.8 °F | 4.45 in. |
| June | 59.1 °F | 81.9 °F | 4.75 in. |
| July | 62.8 °F | 85.0 °F | 3.84 in. |
| August | 60.1 °F | 82.8 °F | 4.17 in. |
| September | 50.9 °F | 76.8 °F | 3.06 in. |
| October | 38.2 °F | 63.6 °F | 2.23 in. |
| November | 25.2 °F | 47.4 °F | 1.38 in. |
| December | 15.3 °F | 33.9 °F | 1.11 in. |
| Annual | 37.1 °F | 59.5 °F | 31.66 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 5a : -20°F to -15°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 |