Headlines proclaiming this week's "Midwest weather the coldest in decades", though not entirely wrong, are misleading. The original headline was referring to a forecast for Chicago of 29 below zero this morning, which would be — if it happens — the coldest reading there since 1985. So that is factual, but only if the forecast verifies.
However, the implication that this is the coldest weather in decades over the entire region is not truthful at all. Locally, the temperatures we have been experiencing are overall around the coldest since 2004, which is 15 years ago. The biggest truth bending occurs when reporters and news writers take a headline from another story and use that as a fact without checking out the fact. The idea is, in principal, correct if imprecise. But for the record, the weather around here this week has not been the coldest in decades.