Why does my hair stop being frizzy in high humidity?

~I've already posted this on r/curlyhair but I also wanted to get your guy's opinions~

I have roughly a 2a-b hair pattern and it tends to be super frizzy. I have these little super curly whispies (they don't match my hair texture) that make an almost cloud around my head. My hair is also in general just pretty frizzy.

I recently noticed that if I let my hair dry then go back into the humid bathroom, my hair starts to have tighter and more defined curls/waves, be a little shinier, and be less frizzy.

Does anyone know why my hair does this? I could only find information on people's hair that gets frizzy in high humidity, not low humidity.

Routine:

1. "Garnier Fructus Sleek and Shine" (Shampoo)
   • I wash my scalp (down to about the nape of my neck) and use any access on the bottom length of my hair. I then I immediately wash it out
2. "Garnier Fructus Triple Nutrition" (Conditioner)
   • I finger comb it into the ends of my hair and any access going on the top of my head/hair. I partially rinse it out once I've washed my body
3. I let it air dry, no additional products.
4. Other notes
   • I tend to take showers on the hotter side
   • I don't know my hair porosity
   • My hair tends to get oily within just a day or two of not washing
   • My hair length is just past the tops of my shoulders
   • My hair dries relatively quickly (maybe about an hour after towel/t-shirt drying, give or take)