What Wikipedia says about the Rudyard Kipling proclaimed 8th Wonder of the World:
With a mean annual rainfall of 6,813 mm on 182 days a year, a high level even for the West Coast, Milford Sound is known as the wettest inhabited place in New Zealand and one of the wettest in the world.
So we were mentally prepared for a fairly wet kayaking experience which we had to book many weeks in advance. And the evening we arrived at the sound (it’s actually a fiord) it all seemed like we would drown in the rain that came down in hordes of cats and dogs. But then at 9pm the sky suddenly cleared and would not reveal more than a few tiny clouds until the end of the next day, leaving us with a scenery you would normally only find on postcards. Thank you!