Spring's arrived to the South Island, with a rollercoaster of weather - including thunderstorms

Heavy rain and strong wind warnings are in place for the Canterbury headwaters for the next couple of hours, while a snow warning's been issued for Lewis and Arthurs Pass.

Seven thousand lightning strikes also hit the mainland this morning.

MetService Meteorologist Silvia Martino says it's a standard set up for spring, as fronts move through briskly.

She says it's quite unusual for lightning to make it across the divide, as it's often trapped on the West Coast.