Weather: 'Bitter' cold change, risk of more thunderstorms

New Zealand faces a "bitter cold change" and the risk of more thunderstorms as spring chaos arrives "bang on schedule".

As a large front crossed northern New Zealand early on Sunday morning, residents were rattled by more than 800 lightning strikes over the upper North Island and around 13,000 over the surrounding waters. These could continue later on Sunday and into next week.

"As the atmosphere remains unstable over northern New Zealand there's a risk of further thunderstorms today and on Monday," MetService warns.

"The outlook for the start of the working week is for rain to return to northern New Zealand (along with the risk of thunderstorms), and a heavy rain watch has been issued for Coromandel Peninsula and western Bay of Plenty."

While the top of the country has a warmer than average day on Sunday, the eastern side of New Zealand has a "fairly bitter cold change" moving up much of both islands. WeatherWatch says this is spring chaos arriving "bang on schedule".

"A high south of NZ is pulling up a fairly cold southerly," WeatherWatch says.

"The entire eastern side of New Zealand from Southland as far north as Gisborne and East Cape will be below normal on Sunday by a few to several degrees with many places having highs in single digits."

The South Island will also see cold temperatures ahead. NIWA says over the next few days, much of the island will be exposed to a southerly quarter flow of air, resulting in colder than average temperatures.

Newshub.