The heat stays on in the North Island as many people return to work today, while most of the east of the South Island has a cool break from recent sweltering weather that saw temperatures up near 34 degrees Celsius.
Niwa Weather recorded 33.8C at Wakanui, southwest of Christchurch, on Saturday, which it said was the highest temperature of the summer so far.
On Sunday, MetService recorded 33.2C at Blenheim and 32.9C at Picton Airport.
Overnight Saturday was one of the hottest nights on record in Canterbury, with many places hovering around 24-25C through the dark hours, while the lowest it got at Christchurch Airport was 22.5C about 4am on Sunday.
That made it the second warmest night at the airport since records started there in 1954.
During last summer, which was the hottest on record, the highest temperature recorded was 38.7C at Alexandra on January 30. The highest temperature recorded in New Zealand is 42.4C at Rangiora on February 7, 1973.
On Sunday, South Island temperatures had taken a bit of a dip as a result of a southerly, but by Wednesday temperatures were expected to be rising again, says MetService meteorologist Tui McInnes.
Heading back to work tomorrow? A look how the week is shaping up in 30 seconds.— NIWA Weather (@NiwaWeather) January 6, 2019
Some highlights for the week:
-Little/no rain for most of the NI
-Any meaningful rain (generally) confined to the west coast of SI
-Generally warm for the NI
-Cool snap late week SI
"The North Island stays more consistent, although Tuesday has a bit of a dip because the southerly pushes up into the North Island."
Wednesday and Thursday were looking warm, but it looked like another front would cool things down a bit from Friday, says Tui.
"At the moment it looks like it pushes up the South Island and possibly into the North Island. It's hard to say how far up the North Island it goes."
MetService is forecasting a high of just 21C in Christchurch on Monday, but the city is expected to be up to 28C by Wednesday and Thursday.
It stays warm in the east of the North Island with Hastings expected to get to 29C, and Gisborne to 30C.
Temperatures could drop a few degrees in the next couple of days, before lifting again on Thursday and Friday.
Temperatures in the upper North Island look likely to stay in the mid to high 20s during the week.
Niwa Weather says little or no rain was expected for most of the North Island during the week, while any "meaningful" rain would be generally confined to the West Coast.
The lower South Island had some decent rain on Sunday, with MetService recording 33.2mm in Dunedin, which had reached 32C on Saturday.
Alexandra had 31mm, Gore 40.2mm, and Milford Sound 168mm. MetService expects high pressure to dominate the country's weather during January, although more so for the first half of the month.
"Into the second half of January the high pressure starts to recede into the north Tasman Sea, allowing south-westerly winds to bring healthier rain, particularly for lower parts of both islands," says the MetService monthly outlook for January.