Heavy snow falling over the lower South Island is expected to ease this afternoon.

Central Otago, Southern Lakes and northern parts of Southland have had a heavy dump of snow.

Meteorologist Tui McInnes says snow will continue into the early hours of tomorrow.

"But we are kind of at that peak now and certainly going to see an even into the coming hours into tomorrow."

However, the upper South Island and lower North Island can expect thunderstorms and heavy rain as severe weather moves up the country.

McInnes says snow will turn to rain as the severe weather moves north.

"Unfortunately, the weather system does linger around, so it will stay wet for most of the week."

MetService has issued a heavy rain warning for coastal Otago.