What happens to your breath when it is -90 degress Fahrenheit outside?

Answer 1

The water droplets in your breath would simply freeze more quickly than when it is a less extreme temperature (e.g. 10 degrees Fahrenheit). Your breath may appear to "sink" more quickly than in more normal temperatures, but little else would change.

However, the likelihood of -90 degrees Fahrenheit in populated areas, those outside of Antarctica, the extreme Arctic, and the peaks of tall mountains, is small-even in those areas. The coldest temperature ever recorded was -129 degrees Fahrenheit at Vostok Station, Antarctica on July 21st, 1983; so while -90 degrees is certainly possible, it is incredibly unlikely outside of the poles and the tops of the tallest mountains in the world.