In reply to bpmclimb:
Hi Brian,
I've stayed around that area in December before, we didn't climb at Layva but was climbing at Oriheula/Callosa and managed a couple of 4 pitch routes in a day (approx. 400m total). We had nice weather, it was warm and dry, but as you say you can't be certain of that. The mornings did start a bit cold and daylight fades fast but it's all manageable.
It's certainly quieter down there rather than around Calpe and worth a visit.