In reply to thomaspomfrett: Hi Tom,
I spent much of my early(better days) climbing at Gogarth and Holyhead Mountain:
Holyhead mountain dries quickly due to the wind coming off the sea; the downside to that is it can be absolutely perishing belaying at the top/climbing. Catches the wind due to it's location.
Gogarth- as you know, Gogarth can be a pretty serious place if the weather comes in; Wen Zawn is pretty cold in the winter as said above it doesn't get too much sun. Castell Helen could be a good option with a few VSs to go at: Lighthouse arete, low in the grade and quite friendly- nice introduction to Gogarth, pel and Rap are also good. Shouldn't be as cold on these.
My advice would be to aim for something light Lighthouse arete; if you lead E1 drop a grade or two for your first Gogarth outing so you have enough in reserve if the weather turns etc.
Enjoy it, on a nice winters day Gogarth can be excellent.
C