There is often wind if you know where to look, it all depends on wind direction. Muriwai is wild west coast anything with west in it, big waves Orewa in NE, small waves There are places (e.g. Shoal Bay, Eastern Beach, Pt Chev) in the city but can be really gusty and lots of shells in places. Keep an eye out for squalls, seems to be more than usual this year.
If there's wind from any direction at all you can kite in Auckland. Theres beaches for evey angle imaginable. Its 40 mins from the west to the east coast. Auckland is definatly not week on wind. particularily this time of year the spring westerlies are hitting hard. As simon says. Watch for squalls. you can have 4 seasons in an hour in nz. 10 to 40 knots in a matter of minutes.