A road snowfall warning has been issued for State Highway 1's Desert Rd for the first day of level 2.

MetService says snow showers are expected to affect the road tomorrow, when 2cm to 4cm of snow is expected to settle near the summit, and lesser amounts down to 800m.

The warning covers 9am to 9pm Wednesday, with an update due tonight at 10pm.

New Zealand outside Auckland moves to Covid-19 level 2 at 11.59pm tonight, meaning more inter-regional travel as many level 3 restrictions lift.

Meanwhile, thunderstorms, gale-force winds and heavy rain were set to strike the flood-hit Auckland region this afternoon.

A strong wind watch was also in place for Auckland until 7pm tomorrow.

Strong winds will mainly affect the western North Island and Auckland with MetService forecasting gusts of 100km/h in exposed places.