Union (WI) Temperature by Month

Union in Wisconsin, United States of America sees significant seasonal temperature differences, with daytime highs between -5°C (23°F) in January and 28°C (82°F) in July, averaging 13°C (55°F) annually. Explore the full monthly breakdown below.

Visitors to Union will encounter a climate influenced by big temperature differences across the year. Nighttime temperatures range from 16°C (61°F) in July to -15°C (5°F) in January.

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

Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM.

The chart below shows the average temperature throughout the year:

Union'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:

Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.

Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.

Boston, USA averages 16°C (61°F) annually, with four distinct seasons and cold winters that rival northern Europe.

Melbourne, Australia averages 20°C (68°F) annually, known for unpredictable weather, with four seasons sometimes happening in one day.

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.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

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