Can blow dries make hair.... drier?

[RainbowConfusion]

I have bra length waves, my hair is naturally slightly porous and frizzy, but with some TLC has calmed down a good bit in the past few years and looks quite nice left natural.
It is in good condition generally and not coloured.
It doesn't curl, no matter what method I have tried, but has some very bouncy waves.

Sometimes I like to wear it smooth as I find it neater and easier to keep out of my face especially in summer. On these occasions I will do a medium heat blow dry that takes 10 mins with a ceramic round brush, Parlux drier and a Kerastase moisture nourishing heat protection. Kind of like how a stylist would do it.

Since spring my hair seems to be a good bit drier in appearance. It doesn't like humid weather and our house does trap humidity, but it even feels drier and crunchier to touch - except it is also really soft .
Could this be from the occasional blow dries?
I only do it once per week so it seems a bit odd.
It isn't damaged or split, and is growing nicely.

If I use a straightening brush it doesn't feel as dried out, but I don't like the flattening effect. I would imagine a blow dry one a week is far more healthy for the hair than a straightening brush, surely? or could I be wrong?

Any tips from someone with similar hair?

Sounds like we have very similar hair! Not sure of your age, but I've found going through perimenopause seems to have made my hair more prone to dryness. I use a very gentle sulphate-free shampoo, and try to only wash my hair 2/3 times a week ( sometimes no shampoo at all and just co-wash. ) Deep conditioner every time. Blow drying your hair does of course dry it out, but seeing as you're using a heat protector, and if your routine hasn't changed, it shouldn't be drying it out anymore than normal IYSWIM. Or are you saying you blow dry it more in Spring / Summer to keep it out of your face? Leaving your hair till it's 80% dry before using the hairdryer will help as it cuts down heat exposure and you can use a microfibre towel to get it to that level fairly quickly.
The other things that make a difference for me is putting Argan Oil on lengths and ends once a week and leaving it for as long as possible / overnight ( the day before a full hairwash ) the pure stuff does smell a bit like a stable though so not great if you are very sensitive to smells or your partner is! And those silk bonnets are great - when I remember to put mine on before bed the difference is marked it the morning and hair is literally silkier - although they aren't exactly alluring to wear, so maybe silk pillow cases would be a better option if that's a concern.

Thanks for such a thought-out reply!

It's tricky, since I take all of the precautions you mention. I wash with Kerastase masqueintense and occasionally head and shoulders to remove crap. It has been great for past 6 months but has recently, suddenly altered texture.
This very well might be my hair responding to environment, since it has always had what i would call 'moods'.

It is as if the texture has gone more porous and fuzzy for seemingly no reason.
It has been like this forever really on and off, I am now 50, and no longer having periods.
It doesn't seem to have altered much with age or meno tbh.

I went to Scotland for a few months last year and the condition improved immediately. It was as if it had an injection of moisture, but my routine had not altered! Also a trip to the lake district in January made it silky and perfect straight out of the shower.

So I wondered if it was the local water, but I live in the ribble valley area of the north west and according to our supply, we don't have hard water here.
I tried washing with distilled water and it got worse

I do wonder about blow drying though as you leave the heat on it for longer than a quick pass with a straightening brush - plus you are tugging at it a bit more..

It's funny, as I wrote all that out I thought bloody hell I'm putting a lot of effort into stopping my hair being frizzy! I guess the Head and Shoulders is a clarifying shampoo so will strip your hair a bit - but it sounds like you really know your products and aren't using it often anyway. I think you're right about the hairdryer causing more tugging and therefore more damage, my hair is fine so the air tangles it easily, but I don't have a straightening brush to compare it too. I've just bought the Kerastase 8hr overnight serum which has rave reviews but have only used it twice - if turns out to be a miracle worker I'll let you know, and if not I guess moving to the Lake District is the next obvious step 😂💁

Thanks Breezy, I hope you have some success!
I don't get along with oils sadly.

I think my hair type does have moods and is very changeable, which often makes us feel like there's something wrong with it, when it's just...nature?

I would love to try the new glossy range from kerastase, but fear it would be a waste, since I have decent ones already.

The wavy/curly threads on reddit are great but most seem to have low porosity, so their hair isn't as candy floss poofy as mine. Growing it longer has helped to weigh it down a bit. Not to make light of it, but it is like my hair is bi-polar.