I’d say it’s medium warm for a synthetic jacket (I have warmer and colder synthetic jackets). While the size is Small, it’s generous, like other belay jackets. I’m often a small or medium in other brands - this has room to spare for me, so great for throwing over other layers.
Photos available via email.
I’m in Leeds and would prefer pickup. It can be posted if you pay via PayPal. Postage would be £5.