Germantown, Wisconsin has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37.2 °F (low) to 55.9 °F (high). Annual precipitation averages 35.5 Inches. Germantown is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.1 °F | 27.5 °F | 1.78 in. |
| February | 14.9 °F | 31.2 °F | 1.65 in. |
| March | 24.2 °F | 42.2 °F | 2.08 in. |
| April | 34.9 °F | 54.9 °F | 3.88 in. |
| May | 45.7 °F | 66.7 °F | 4.01 in. |
| June | 55.5 °F | 76.5 °F | 4.37 in. |
| July | 60.8 °F | 81.4 °F | 3.98 in. |
| August | 59.1 °F | 79.6 °F | 3.65 in. |
| September | 51.2 °F | 72.6 °F | 3.18 in. |
| October | 40.0 °F | 59.6 °F | 2.8 in. |
| November | 28.9 °F | 45.3 °F | 2.14 in. |
| December | 18.7 °F | 33.1 °F | 2.0 in. |
| Annual | 37.2 °F | 55.9 °F | 35.52 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |