Germantown Hills, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.8 °F (low) to 61 °F (high). Annual precipitation averages 38.5 Inches. Germantown Hills is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.5 °F | 31.9 °F | 2.14 in. |
| February | 18.8 °F | 36.7 °F | 2.05 in. |
| March | 28.5 °F | 48.9 °F | 2.56 in. |
| April | 39.6 °F | 62.1 °F | 3.83 in. |
| May | 51.2 °F | 72.9 °F | 4.69 in. |
| June | 60.9 °F | 81.8 °F | 4.47 in. |
| July | 64.2 °F | 84.9 °F | 3.79 in. |
| August | 62.1 °F | 83.3 °F | 3.52 in. |
| September | 54.2 °F | 77.9 °F | 3.5 in. |
| October | 42.5 °F | 64.9 °F | 3.12 in. |
| November | 30.9 °F | 49.8 °F | 2.7 in. |
| December | 21.2 °F | 37.2 °F | 2.09 in. |
| Annual | 40.8 °F | 61 °F | 38.46 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |