Below is a screenshot of the forecast in Portland this week, as reported by the local newspaper The Oregonian. Notice the lows in the mid-20s being described as “very cold.”
And here’s the forecast from The Tribune. Notice the lows in the teens are described as moderate.
In Chicago, we don’t throw “very cold” around willy-nilly, you gotta earn it. Although, I do like how they soften the blow by prefacing with “mainly sunny but… ”