sade087

A very science-y post. Fun! ©Science-y Hair Blog 2013 Dewpoint and relative humidity and how they effect hair has been swirling around my mind this spring as we have had some really variable weather. I live where winters are usually cold and dry, summer is usually hot and humid and spring and fall are combinations of everything. Dewpoint and relative humidity are not easy to understand. They're in the realm of physics - things like “saturation air pressure” that we experience every day and know what they are from experience. But when we try to measure them and predict and explain their effects on other complex systems like hair – Man! It’s not easy. Here’s what is wonky: Dewpoints getting into the “moderate” range, but dry air. You think your hair should be bouncy and defined, but instead it wants to be limp. But the dewpoint is above 40°F, you think – so what gives? When you go outside, your lips and eyes and mouth dry out and your waves and curls lose their spring or feel rough. ...

The last post was all about the dewpoint. On a normal day, that's the measurement that tells you how much water you might expect to be in the air - so you know whether your skin and hair will be dehydrating or not. ©Science-y Hair Blog 2013 Relative humidity is how much moisture the air is actually holding right now, vs. (relative to) how much it can possibly hold (the dewpoint). I am looking at a temperature of 67°F (19°C) with a dewpoint of 60°F and a relative humidity of around 80%. This is very juicy air! We are expecting strong storms from an air mass like this. It is usually foggy and very dewy in the morning when the air temperature is this close to the dewpoint and it's not very cold . When the dewpoint is close to the temperature, the air is wet. I think this is some of the worst "weather" for maintaining bouncy waves and curls because the moisture is being taken on by the hair and the wave and curl is expanding in some places, tightening in others and just n...