The West Coast has about 2000 mm of rain every year - more in the south. It's possible to go there and find glorious sunny weather, but it's best to be prepared for rain. While we were there, we experienced a pattern of rain at night and sometimes into the morning, clearing in time for warm sunny afternoons, and clouding over again by the evening.
It was sunny and hot while we were at Shantytown, but by the time we arrived at Hokitika that evening it had clouded over again, so our excursion to the beach to watch the sunset was rather doomed to failure. This is the best we could manage:
But despite the lack of sunset, the following two photos really appealed to me (even though the second one is technically rather unsharp, due to the low light and lack of a tripod):