Bronson, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37.2 °F (low) to 59.7 °F (high). Annual precipitation averages 30 Inches. Bronson 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 | 9.8 °F | 29.2 °F | 0.63 in. |
| February | 14.1 °F | 34.1 °F | 0.82 in. |
| March | 25.0 °F | 47.4 °F | 1.6 in. |
| April | 36.0 °F | 60.9 °F | 3.21 in. |
| May | 48.5 °F | 72.0 °F | 4.19 in. |
| June | 59.5 °F | 82.1 °F | 4.65 in. |
| July | 63.0 °F | 85.3 °F | 3.44 in. |
| August | 60.6 °F | 83.2 °F | 3.87 in. |
| September | 51.1 °F | 77.0 °F | 2.94 in. |
| October | 38.2 °F | 63.8 °F | 2.28 in. |
| November | 25.2 °F | 47.5 °F | 1.4 in. |
| December | 15.0 °F | 33.9 °F | 0.97 in. |
| Annual | 37.2 °F | 59.7 °F | 30 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 |