Waterproof trousers that aren't plasticky??

[Ialwayswannasometimes]

I need some waterproofs for my DS for forest school but he absolutely won't wear the plastic feeling ones.he's autistic and finds them really annoying both in how they feel and the noise they make!
I've seen "water repellent" ones in trespass etc but I'm not sure how waterproof they are
he'll be outside in the rain for 4 hours so they do need to be fairly waterproof. I thought about maybe ski pants but would that be far too hot?
does anyone have any recommendations

Would he wear fleece lined ones?

'Softshell' is what you need to search for. Traditionally softshell is showerproof not waterproof, but more and more waterproof softshell is being made, so if you search for 'waterproof softshell' you should get some options.

e.g.
www.amazon.co.uk/Sidiou-Group-Softshell-Waterproof-Windproof/dp/B076M2LBDR?th=1
www.polarnopyret.co.uk/products/unisex-black-lined-waterproof-kids-trousers-60480833-198?gclid=EAIaIQobChMI0_uBs5q1-wIVgd_tCh3SbwErEAAYAyAAEgJHdPD_BwE

Have a look for flexothane. It is what farmers use. They are rubbery, not crinkly. If you have a Mole Valley near you you should find some in there, or farm/country stores online.