Brownstown, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.3 °C (low) to 18.1 °C (high). Annual precipitation averages 1250.7 Millimeters. Brownstown is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.4 °C | 3.9 °C | 92.96 mm |
| February | -4.2 °C | 6.6 °C | 75.18 mm |
| March | 0.1 °C | 12.2 °C | 105.41 mm |
| April | 5.6 °C | 18.8 °C | 135.38 mm |
| May | 11.7 °C | 23.8 °C | 136.65 mm |
| June | 16.3 °C | 28.1 °C | 128.52 mm |
| July | 18.2 °C | 29.8 °C | 106.43 mm |
| August | 17.1 °C | 29.4 °C | 98.3 mm |
| September | 12.8 °C | 26.3 °C | 86.36 mm |
| October | 6.1 °C | 19.8 °C | 91.69 mm |
| November | 0.8 °C | 12.4 °C | 98.04 mm |
| December | -3.2 °C | 6.2 °C | 95.76 mm |
| Annual | 6.3 °C | 18.1 °C | 1250.68 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |