Germantown (WI) Temperature by Month

Germantown, Wisconsin, United States of America has an average annual maximum temperature of 13°C (55°F), ranging from -3°C (27°F) in January to 28°C (82°F) in July. Below you'll find a full monthly breakdown and a comparison with cities worldwide.

With significant temperature fluctuations, Germantown enjoys distinct seasons year-round. Nighttime lows range from 16°C (61°F) in July to -12°C (10°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Germantown by month:

The minimum temperature is often recorded between 4 AM and 6 AM, while the highest temperature is usually reached at 3 PM, when the sun's heating effect is strongest. July, the warmest month, gets 330 hours of sunshine.

The chart below shows the average temperature throughout the year:

Germantown's average annual maximum temperature is 13°C (55°F). To put that in context, here's how it compares to a few well-known destinations:

Rome, Italy averages 20°C (68°F) annually, with reliably warm summers and comfortable winters.

On the cooler end, Oslo, Norway averages just 10°C (50°F) annually, with pleasant summers but long, cold winters.

Chicago, USA averages 15°C (59°F) annually, known for extreme seasonal swings, from bitterly cold winters to warm summers.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Seasonal temperature shifts influence more than just how warm it feels, they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.

Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Germantown this rarely lasts long on the ground.

For more on Germantown's weather, including monthly rainfall, sunshine hours, and humidity, visit our Germantown climate page.