yeah there is riding - we don't get really really cold days like in some parts of Nth America. Right now (12:30 on Sunday afternoon - it is 15 C in Auckland (although not a good example because it looks like there is a thunder storm there) and 8 C here in Christchurch. I got out on the road bike yesterday and it was fine for riding. One of the main mountain biking areas here - bottle lake - is quite close to the sea so it is sandy and rideable unless it has really been raining very hard.
What kind of riding are you wanting to do?
In terms of other travel stuff are you primarily here for business or all for pleasaure? What are you interested in other than cycling?