• Q&A

Chicago, Climate Change And Weather: Your Questions Answered

What’s The Difference Between Weather And Climate?

People walk on the sidewalk during a snowy day in Chicago
People walk on the sidewalk during a snowy day, Sunday, April 14, 2019, in Chicago. Nam Y. Huh / Associated Press

To kick off our weekly climate conversations, it’s important to understand what we’re talking about when we say “climate.” What’s climate, what’s just weather, and how do the two relate?

Illinois state climatologist Dr. Trent Ford boiled it down this way: “Climate is really what we expect, and weather is what we get.” According to Ford, weather describes the atmosphere at a certain moment, like in a weather forecast. Climate describes the statistical average over time.

For example, based on climatological averages, the expected last day of snowfall in the Chicago area is around April 4. But the weather we get differs year to year. Ford said in 2012, the last day of measurable snow was March 4. In 2019, there were more than two inches of snow at O’Hare on April 27.

To hear the full conversation, click the red LISTEN button above.