New Zealand’s West coast is known to get a lot of rain, and it didn’t let me down in that regard. I had days that it was raining so hard that you wouldn’t want to leave the car even for a walk across the highway. Roads were being washed out, and campgrounds flooded. I can hear you now saying “Sign me up for that fun!” Well it wasn’t all doom and gloom. The area is beautiful and worth the trip. I would just suggest giving yourself a couple of extra shoulder days just in case the weather isn’t cooperating. I missed out on a skydive @ Fox Glacier which is purported to be one of the best spots in the world to jump out of a plane due to the iffy weather.
The warm and wet air coming from Australia across the Tasman Sea is forced up when it hits New Zealand's Southern Alps and dumps rain right on the West coast region. This gives the area its thick forests and plenty of waterfalls.
The west coast is home to a pair of very accessible glaciers (Franz Josef & Fox glaciers, by tour) that flow right into the rainforest, old gold mining towns, interesting Earthquake spots, amazing geological formations and dramatic coastline. I spent a few days in the area watching beautiful sunsets over deserted lagoons, visiting the relics of the gold rush, squeezing through the Pancake Rocks and trying to keep dry.