Brown Deer, Wisconsin has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.2 °F (low) to 56.9 °F (high). Annual precipitation averages 35.1 Inches. Brown Deer is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.7 °F | 29.5 °F | 1.7 in. |
| February | 17.4 °F | 32.9 °F | 1.64 in. |
| March | 26.2 °F | 43.1 °F | 2.01 in. |
| April | 36.1 °F | 55.0 °F | 4.02 in. |
| May | 46.7 °F | 67.0 °F | 3.94 in. |
| June | 56.9 °F | 76.8 °F | 4.48 in. |
| July | 62.5 °F | 81.8 °F | 3.55 in. |
| August | 61.6 °F | 80.3 °F | 3.57 in. |
| September | 53.8 °F | 73.5 °F | 3.23 in. |
| October | 42.3 °F | 61.0 °F | 2.85 in. |
| November | 30.9 °F | 46.7 °F | 2.08 in. |
| December | 21.0 °F | 35.0 °F | 2.02 in. |
| Annual | 39.2 °F | 56.9 °F | 35.09 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |