The bitterly cold blast that has hit New Zealand this week should ease off over the coming days, but heavy snow is still expected overnight in many areas, including Wellington and Christchurch.

Snow returned to the nation's capital this afternoon, with a late afternoon surge seeing the the temperature plunge to just above freezing with a wind chill of -5, according to weatherwatch.co.nz

The polar surge in the capital forced police to close roads, including the Rimutaka Hill Road, Wainuiomata Hill Road, Paekakariki Hill Road, and State Highway 58 between State Highway 2 to Moonshine Road and Blue Mountains Road in Upper Hutt.