text: how cold does it have to be outside before you can see your own breath? the question is pretty much self explanitory. depends on the humidity- your breath has to have enough water vapor in it that it condenses in the air when you breath out.  so, if it is, say, 50 degrees outside but extremely humid, you could see your breath, because the air is already saturated with water and can't hold any more.  but, in very dry air, it has to be significantly colder before you see your breath, because the air can hold a lot more water when it's dry.  however, because cold air can hold less water than warm air, there is a certain point at which you will get condensation no matter how dry the air is..