The weather across the nation is making roads dangerous for travellers.

The New Zealand Transport Agency says in the South Island, snow means chains are essential on the road to Mt Cook, Arthurs Pass, Haast Pass and the Crown Ranges, and those routes are closed to towing vehicles, however the Lindis Pass road is now open again.

In the North Island, SH2 between Napier And Wairoa is dangerous to travel because of numerous slips and fallen trees.

That road is down to one lane in parts.