I almost bought my last pair of hiking shoes here, went somewhere cheaper for same model but slightly uglier and probably older, but cheaper. I think it’s a good shop:
Danshui is like 15 miles from Taipei, with no major geographical features to block weather (I guess that little hill they call a mountain in yangmingshan can divert some, to some extent, but it ain’t the sierras there). I’ve got family in Danshui and Chuwei, but stay in Taipei and take the mrt back and forth every day when visiting - there’s rarely a big difference in weather.
Not really colder in winter. Again, the ocean has a slight moderating effect. It can get pretty dismal sometimes when the northeast monsoon is blowing though.
Be sure to get a couple of cookies to be washed down with your coffee. If you order them at your table, they’ll make you go outside to buy them, which will then be served on a nice plate. That’s old school!