Think very good advise to have clothes you can layer. It can be glorious weather in the day time, then when the sun goes, which will be around 15.30 in the winter, the temperature drops considerably.Some Decembers/January's can be OK, other years, lots of rain. So I would say to leave shorts, but really, light weight trousers better. Jeans good also for the evenings and for bad weather days. You can buy fleeces etc here of course. And yes, hopefully t shirt days! But always take a fleece/sweater out with you at that time of year!