"In my infinite wisdom," LOL ( ; I'm not greying so I have no advice there, only to say that white at the temples is a fetching look.
Re: "in between washes," is there some particular change that you notice in your hair/its "behavior" between washes? Longer hair and especially wavy/curly hair tends to want moisture, but if you're not noticing any ill effect from simply leaving it alone, well--if it ain't broke, etc. etc.!
I'd definitely recommend covering up your hair when working outside in rough weather. I used to do ranch work and vividly remember the aggravation of getting my braid caught on things, not to mention going back indoors with cold/wet hair : P A very quick solution, if your scalp will tolerate it, is to secure your hair up at the top of your head (topknot, top pony, whatever you prefer) and pop on a stocking cap. A bandana does the same job nicely in warmer weather.
Clumping in general is prototypical of wavy hair, but if the "rat tails" are a new development since these last two washes and not what you'd typically experience, they suggest your hair is being weighed down by something. It's unclear to me from what you've written if the "coconut oil based product" is the conditioner you're using, or something else. You could certainly try a more thorough rinse next time and see if that changes anything. I always have trouble rinsing out my hair all the way, and find that combing/brushing it as I rinse helps get right down to the scalp.
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