Estimated read time: 2-3 minutes
This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.
What is the temperature at which you can see your breath? I've tried to figure this out by observation, but I haven't nailed it down precisely. Thanks, Pam
**********************************************************
Great question and it shows you are totally thinking about all things weather. Now some nights you can see your breath when you breathe into the cold air. But other nights you can't. In the summertime during the day time, you can't see your breath at all (usually that is) on a sunny day. But then sometimes at night, you see, then you don't, what's going on with all that crazy air?
Here's the deal and let's review some basic stuff. When put ice cubes into your water glass and leave it out for a few minutes you get condensation on the outside of the glass. Now the did the water move through the glass, can water do that? Nope. But the air around the glass was cooled to its dewpoint and condensation formed on the glass.
The same is happening when you breathe into the cold air. Your breath is full of warm moist air, it has a lot of water vapor. When it comes out of your mouth, it cools off and condenses, that is the little cloud you see coming out of your mouth. Water vapor will condense at its DEWPOINT and the dewpoint changes all the time so you can't pinpoint a temperature when your breath will condense.
You can see your breath at 45 degrees and you can see it at 10 degrees, it's all about dewpoint. The air coming out of your mouth has to cool off. Your breath will condense at the dewpoint temperature not the air temperature and the dewpoint changes all day long.
You can check current temperatures and dewpoints at the link on the right and you can also check out how they change all day. Just click on the city you want to get the current observation.
Answered by KSL Meteorologist Dina Freedman and Dan Pope.
