One last rough patch of weather is on its way before we can settle into a calm December, forecasters say.

The latest surge of late spring weather, which could bring thunderstorms to the South Island, is about to make its way across the country.

But it could be the last for a number of weeks, predicts.

The low will push north over the country tomorrow, bringing heavy rain in the west and more hot winds in the east, said head weather analyst Philip Duncan.


The heat would arrive tomorrow, followed by cooler conditions spreading to most places over the weekend.

"It will be another scorcher in the east, we're predicting Christchurch will hit the late 20s with inland parts of Canterbury potentially hitting the low 30s again," he said.

A hot northerly and north westerly would be moving into Malborough, Wairarapa, Hawkes Bay and Gisborne reaching temperatures in the early 30s.

But heading north, temperatures would be dropping.

"Air temperatures will drop as you head north under cloudier weather however humidity levels will be much higher in the north so it will feel hot and sticky, especially if the sun comes out," Duncan said.

The end of the day could see an increased risk of thunderstorms risks for the South Island as colder air approached from the southern ocean, he said.

These thunderstorms could continue into Thursday morning.

"As I said back in November the spring weather pattern would continue into the start of December - but there's a big chunk of dry, settled, weather coming in from Australia starting this weekend and potentially lasting up until the days before Christmas".