Temperatures are likely to reach 20C in eastern parts of New Zealand this week.

Temperatures in the eastern parts of the country can be expected to reach twenty-five degrees later this week, according to MetService.

MetService meteorologist Dom Barry said warmer air would mean many places in the east would see above-average maximum and minimum temperatures.

“For easternmost locations such as Christchurch, Oamaru, Napier and Hastings, you can expect highs in the mid-twenties,” Barry said.

Temperatures are expected to reach 26C in Christchurch on Wednesday afternoon and 24C in northern Napier.

Temperatures in Napier are expected to reach 26C on Thursday and 23C in southern Christchurch.

“Nighttime temperatures will also remain warm, in some cases just a couple of degrees below daytime highs, which could make sleep difficult for some,” Barry said.

But it’s not all good news for those living in the south, as a series of weak fronts are likely to bring some scattered rain to some.

“Warm and moist northwesterly winds develop over the South Island as we approach Wednesday, bringing rain to the western and southern parts of the South Island,” Barry said.

“There is a heavy rain warning in place for Fiordland from Wednesday to Thursday, which is likely to be upgraded to an orange heavy rain warning in the near future.”

A series of fronts move up the South Island on Thursday, bringing rain to the southern and western parts of the country, while high temperatures move into the north-east of the country. As a result, the north will be mostly fine and dry.

Barry said the warm weather looked set to continue for Hawke’s Bay’s anniversary on Friday, but elsewhere the weather looked more unsettled with wind and rain returning.

“Low pressure returns later this week, meaning we’ll have wetter weather ahead for the long weekend,” he said.

“With drier weather possible on Labor Day, it’s worth checking the forecast to make the most of the weekend.”