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How cold is too cold to run outdoors?

when is it too cold to run

There’s running in the cold, and then there’s running in frigid, sub-zero temperatures with even lower wind chills. Over the last couple days, in wake of the most recent winter storm, there’s been quite a debate going in my group of running friends. It all stems from the question: “How cold is too cold when it comes to running outdoors?” 

Ultimately, we agreed to disagree for lack of scientific evidence and, instead, to refocus our discussion .There are so many factors, ranging from temperatures a runner is used to running in (Florida runner versus Alaskan, for example), the specific weather conditions (windy, snowing, still, etc.), and what’s an acceptable level of comfort (which is, of course, highly individual).

Then a local 10K winter favorite, aptly titled the Freeze Series, was canceled this morning due to “dangerous wind chills.” So, the question was opened back up for even more debate. This time, the factor of safety came out explicitly to weigh our answers and target our speculation.

Is there a temperature when it is actually not safe to run outdoors?

From what I gathered across the web, the answer is yes and, well, no.

Confused? So am I.

  • Many experts agree this threshold is around when the real temperature or wind chill reaches -20 degrees F or below, at which point the risk of hypothermia or frostbite increases exponentially.
  • And let’s forget about villainizing the cold for a minute. “Though cold can be frightening, more people are injured exercising in the heat.” Extremes of any kind are really where the problem occurs.
  • Some experts, though, contend we can’t really put a number on safe. With regard to deep freeze and any concerns with hurting lungs, “No matter how cold the air is, by the time it reaches your lungs, it is body temperature.

Seems like no on can agree entirely. Either way, recognizing that many hardcore athletes might dismiss red weather alerts or ignore their own body’s warning signs, take heed. When extreme conditions exist outdoors, it’s smart to shorten a workout’s intensity/duration and stick closer to your house in case of emergency. And let’s be honest, it isn’t tremendous fun out there in extreme weather, no matter the kind.

I myself can tolerate some pretty chilly temperatures. Still, I like to follow the -20 degree rule. To determine what combination of thermometer read plus wind dips that low, you can consult this handy chart written up by the National Weather Service.

Written by  Ashley Marcin.

More Winter running safety | Guide to winter running