MetService has issued snow warnings for motorists in many parts of New Zealand.

On the Desert Road overnight and in the morning, 15-20cm of snow is forecast, mainly at the summit.

Lewis Pass overnight until late Monday afternoon is in for 4-8cm of snow.

Arthurs Pass is in for 1-2cm of snow overnight, and Lindis Pass can expect 2-5cm overnight.

Overnight and until mid-afternoon tomorrow, 2-5cm of snow is likely on Porters Pass.

On the Milford Road near the tunnel overnight and south of Lake Gunn through until late morning, 3-6cm of snow is expected.

And on the Rimutaka Hill Road, 1cm of snow is likely mid-afternoon tomorrow.