By Heather Brown

MINNEAPOLIS (WCCO) — Later this week, the temperatures are once again expected to dip below zero. That means there’s a good chance your nose will start dripping when you step outside.

So, that had Rachel from Plymouth wanting to know: Why does our nose run when it’s cold? Good Question.

The nose produces about a liter of mucus each day. Most of the time we don’t know it because we swallow it.

But, when we breathe in cold, dry air, many of us develop cold-induced rhinorrhea – better known as skier’s nose.

This happens because our lungs are sensitive and don’t like cold, dry air. It’s the job of the nose to heat and moisture that air before it gets all the way inside our bodies. The nose warms the air by producing more mucus. Sometimes there’s too much and that mucus has to go somewhere — down.

There’s another phenomenon at work. When we see our breath in cold weather, that’s our breath condensing and making little droplets. Those droplets then re-condense on your nose, creating more fluid — and more drip.


Heather Brown