this is a pretty good link Kat http://www.curlynikki.com/2010/06/summer-curls-understanding-dew-points.html

kat180 - 27 January 2011 10:59 AM

I know this is an old thread - but can someone explain dew points and humidity? Or post a link that explains it?

Are they two different things and what do they mean for your hair?

What is a high humidity/dew point and a low one lol?

The link chm posted also contains clickable links in the article

Here’s some more:
http://www.wmur.com/askthemeteorologist/2920693/detail.html
http://coloradocurly.wordpress.com/dew-point/
http://www.curlynikki.com/2009/04/curl-whisperer-on-humidity.html
http://www.britishcurlies.co.uk/articles/article/uk_weather_and_your_curls/
http://livecurlylivefree.blogspot.com/2009/03/where-oh-where-have-my-curls-gone.html

Oh God. Its like being back in science class lol!

I think Im starting to understand it. Just.

So I should avoid things like aloe vera, glycerin, honey, FSG in low dew points?

Its seems my hair is loosing some curl and going fluffy outside because Im using products heavy with these ingredients yes?

But….as my hair likes these….what types of products should I turn to in low dew points/cold weather? (Are they related or have I got it wrong lol) Let me be more specific - please don’t tell me I have found CJ products, only to have to give them up because they seem to have a lot of the ingredients above in them. Or the ones I do have. I think.

Gosh this is hard work.

Here is another link that may be handy http://www.naturallycurly.com/curlreading/ingredients/humidity-humectants-and-the-dew-point

kat180 - 27 January 2011 11:36 PM

Oh God. Its like being back in science class lol!

I think Im starting to understand it. Just.

So I should avoid things like aloe vera, glycerin, honey, FSG in low dew points?

Its seems my hair is loosing some curl and going fluffy outside because Im using products heavy with these ingredients yes?

But….as my hair likes these….what types of products should I turn to in low dew points/cold weather? (Are they related or have I got it wrong lol) Let me be more specific - please don’t tell me I have found CJ products, only to have to give them up because they seem to have a lot of the ingredients above in them. Or the ones I do have. I think.

Gosh this is hard work.

I would say, given the generally okayish dew points here, not to avoid ingredients until you notice problems that you can definitely put down to dew point/ humectant interaction.  Sometimes going fluffy outside is actually due to just not enough hold in general, or the wrong kind of hold.  Hair with a good moisture/protein balance should be more resistant to dew point variation as well (as best I can tell). 

Also, glycerin is the classic problematic humectant, so if you’re going to have problems in low dew points, it will probably be with that one rather than aloe, honey, agave, etc.  There is some evidence, however, that glycerin should not actually cause problems because unless it’s formulated incorrectly, it won’t go seeking more water than it already has because it literally cannot take on more (http://thenaturalhaven.blogspot.com/2010/03/moisture-issue-glycerin-is-your-friend.html - first two comments in particular).  Pure glycerin is one thing - glycerin in a formula is another entirely.  I suspect aloe, honey, etc., work the same way, but to a lesser extent. 

I also suspect, from personal and anecdotal experience, that the dew point - humectant link is actually made out to be too strong.  I think it’s very possible the dew point brings out an underlying sensitivity rather than it being a rule that humectants are problematic in dew points for everyone - most people I know who really can’t use humectants in low dews can’t really use them the rest of the year either.  Aloe in styling products hates me year round - I just only really notice it in drier months. 

All that to say - experiment.  You’ll never know until you try.

Great info Oddity! Mind if I copy and paste it over to the Dew Point thread I made?

I had thought that my hair going fluffy when I went outside after trying out AFG might be linked to lack of hold/too much moisture with all the CJ products rather than being specifically because of humectants. But it definitely helped me to understand it all better by writing up the thread.

Trial and error - its a long process but so much fun!

No problem.  

And yeah, as with all hair things, you can only really diagnose if it’s happened a lot and you can duplicate it several times.  Oh darn - we have to try out all kinds of products!  Such a trial!

I am beginning to wonder if the UK (Manchester) has any high dew days. Even when its been raining the dew points have been relatively low. I haven’t checked every day, but a couple of times a week for the past few months. Do they get higher in summer?

It is making me think about all those products that I use with glycerin in. Is it worth looking at products with lower levels of humectants seeing as though we seem to be getting so few high dew days.

JoeyEmma - 06 April 2011 03:00 PM

I am beginning to wonder if the UK (Manchester) has any high dew days. Even when its been raining the dew points have been relatively low. I haven’t checked every day, but a couple of times a week for the past few months. Do they get higher in summer?

It is making me think about all those products that I use with glycerin in. Is it worth looking at products with lower levels of humectants seeing as though we seem to be getting so few high dew days.

Is your hair doing something different that has made you think like this?

No, my hair is still the same. I was just thinking that the weather is warmer and it has been raining, yet the dew points are still low!

JoeyEmma - 06 April 2011 03:48 PM

No, my hair is still the same. I was just thinking that the weather is warmer and it has been raining, yet the dew points are still low!

lol ok! I thought something drastic had happened! (my dp today is 52F)

Its 44.6 here (7’C). Is that a high or low or mid dew point?

mid - shouldn’t bother hair too much.  Around 65 and you may feel it hairwise (according to what I’ve read)

http://www.timeanddate.com/weather/uk/bristol

This is a good site for dew points

OK, maybe I am on the slow bus but I still don’t get it after reading the various articles on dew points.

People keep giving dew point ranges of when certain products should work best but this all seems to be too simplistic to me if the temperature is also a variable which creates the relative humidity.

Take today for instance.  The dewpoint is 15 degrees, which according to the articles should be prime curly range.  However the temperature is only 16 degrees so humidity is 94 percent.  That doesn’t seem very prime hair weather to me!

I’m afraid to wash my hair for fear of it going up like ball of smoke in the dampness of the air.

So should I treat today like its a high dewpoint day since the dewpoint is close to the air temp?  Or does that not matter because the air is still only holding water at a certain limit?