Summary: If you’ve ever hiked to the top of a mountain and found yourself shedding layers of clothing because of increasing warmth, you’ve experienced a temperature inversion. They’re strongest in winter and can come with some unpleasant side effects, such as the freezing fog and declining air quality the greater Puget Sound region recently experienced in mid-December. Temperatures in the lowlands were near freezing at the time, but hit 55 degrees at Hurricane Ridge in the Olympics.
