Countryside (IL) Temperature by Month

Countryside in Illinois, United States of America sees significant seasonal temperature differences, with daytime highs between 0°C (32°F) in January and 29°C (84°F) in July, averaging 16°C (61°F) annually. Explore the full monthly breakdown below.

Depending on the time of the year, temperatures range from comfortable to very cold in Countryside. At night, minimum temperatures range from 19°C (66°F) in July to -8°C (18°F) in January.

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

From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak. July, the warmest month, averages 319 hours of sunshine.

The chart below shows the average temperature throughout the year:

Countryside's average annual maximum temperature is 16°C (61°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.

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

Osaka, Japan averages 22°C (72°F) annually, with hot humid summers, mild winters, and pleasant spring and autumn seasons.

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

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 Countryside, January is the coolest month, with average highs of 0°C (32°F) and humidity around 72%, considered high. In July, the warmest month, temperatures average 29°C (84°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.

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 Countryside's weather, including monthly rainfall, sunshine hours, and humidity, visit our Countryside climate page.