Waukegan (IL) Temperature by Month
Waukegan, Illinois, United States of America has an average annual maximum temperature of 14°C (57°F), ranging from -1°C (30°F) in January to 27°C (81°F) in July. Below you'll find a full monthly breakdown and a comparison with cities worldwide.
Waukegan Monthly Temperatures
Visitors to Waukegan will encounter a climate influenced by big temperature differences across the year. Nighttime temperatures range from 18°C (64°F) in July to -9°C (16°F) in January.
The chart below illustrates the average maximum day and minimum night temperatures in Waukegan by month:
Low temperatures are most often recorded between 4 AM and 6 AM, while highs typically occur around 3 PM. July, the city's warmest month, sees 319 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Waukegan vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
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Waukegan vs World: Temperature Compared
Waukegan'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.
Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.
Buenos Aires, Argentina averages 23°C (73°F) a year, with hot summers and mild winters — and seasons reversed compared to Europe.
Melbourne, Australia averages 20°C (68°F) annually — known for unpredictable weather, with four seasons sometimes happening in one day.
What Does the Temperature Feel Like in Waukegan?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.
In Waukegan, January is the coolest month, with average highs of -1°C (30°F) and humidity around 72% — considered high. In July, the warmest month, temperatures average 27°C (81°F) with 68% humidity — conditions that feel high. For a full picture, see our humidity page.
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 Waukegan this rarely lasts long on the ground.
For more on Waukegan's weather — including monthly rainfall, sunshine hours, and humidity — visit our Waukegan climate page.
