Grafton (WI) Temperature by Month

The average annual maximum temperature in Grafton, Wisconsin, United States of America is 13°C (55°F), with daytime highs ranging from -2°C (28°F) in January to 27°C (81°F) in July. This page covers monthly averages, day-night differences, and how Grafton compares to cities worldwide.

The climate in Grafton is known for significant temperature differences throughout the year. At night, this contrast is just as clear, with lows ranging from 16°C (61°F) in July to -10°C (14°F) in January.

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

The coldest point of the day usually falls between 4 AM and 6 AM, with temperatures peaking around 3 PM. July, the city's warmest month, gets 330 hours of sunshine.

The chart below shows the average temperature throughout the year:

Grafton'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:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

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

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

Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.

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.

Whether a city sits on the coast or deep inland makes a significant difference to its climate. Coastal areas tend to have more stable temperatures year-round, large bodies of water absorb heat slowly in summer and release it gradually in winter, keeping extremes in check. Cities far from the sea don't benefit from that buffer, which is why continental climates tend to have hotter summers and colder winters than their coastal counterparts at the same latitude.

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