Waterloo (IA) Temperature by Month

The average annual maximum temperature in Waterloo, Iowa, United States of America is 14°C (57°F), with daytime highs ranging from -3°C (27°F) in January to 29°C (84°F) in July. This page covers monthly averages, day-night differences, and how Waterloo compares to cities worldwide.

In Waterloo, temperatures can shift dramatically between warm in summer and very cold in winter. Nights follow the same pattern, with lows ranging from 17°C (63°F) in July to -13°C (9°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Waterloo 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:

Waterloo's average annual maximum temperature is 14°C (57°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.

Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.

Seoul, South Korea averages 18°C (64°F) a year, with four clear seasons, cold winters, and hot humid summers.

Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.

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.

Global average temperatures have risen by around 1.2°C since the pre-industrial era, and the effects are visible across many regions. Winters are milder on average, with fewer frost days and less snow in many parts of the world. Heatwaves are more frequent and more intense, and Europe's summers of 2018, 2019, and 2020 all set records.

Summers are also getting drier in some areas, while winter rainfall has increased in others. This contributies to higher river levels and more flooding. In many countries, spring arrives earlier and autumn lasts longer. It has knock-on effects for wildlife, agriculture, and local ecosystems.

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