Winter season in New Zealand takes place in the months June, July and August. NZ's winter isn't as snowy and icy as some people expect. See what winter in New Zealand is all about.
So generally speaking, you do not need chains unless you are looking at doing a lot of skiing or going to particular, smaller roads in the South Island. It pays to watch the weather forecast during the winter and if in doubt stay put as you will be better off than getting stuck in the snow for a day or so.
We can advise you on where to hire chains around the country if required – for example, chains are required by law to travel on the Milford Road between July and October. You can pick a set up in Queenstown from a specialised company there and drop them off on the way back up if you are looking at exploring Milford Sound during these months.