The lakeside township is the pick of the South Island centres, according to MetService.
MetService's website shows a run of three days of temperatures of 30 deg C or higher starting today, before Wānaka eases back to the mid-20s towards the end of the week.
That's warmer than the traditional hotspot of Alexandra, which can expect 30 deg C today before dipping slightly to 27 deg C tomorrow then climbing to 31 deg C on Wednesday.
People on the east coast can expect a pleasant start to the week, albeit without the scorching highs.
Christchurch, Dunedin and Oamaru will all have a run of days at about the 20 deg C mark.
Christchurch is set to peak at 25 deg C on Thursday but there will also be a high chance of rain.
According to MetService, most of the South Island can expect cloudier skies and the chance of some rain towards the end of the week and into the weekend, though temperatures are expected to remain mild.
The fine conditions in the south come as some heavy weather bears down on the North Island.
A subtropical low and preceding fronts will move southwards over its northern parts from today, bringing easterly gales and periods of heavy rain, MetService warns.
A heavy rain watch has been issued from 10pm in Northland, and from Tuesday morning in Auckland and Great Barrier Island as well as the Coromandel Peninsula.
Periods of heavy rain are also expected north of Kaikohe during Monday morning and afternoon, especially in the east.
There is a high chance of the watch upgrading to a warning in Northland, but only a moderate chance in Auckland, Great Barrier Island, and the Coromandel Peninsula.
A strong wind watch has also been issued for Northland, Auckland, Great Barrier Island and Coromandel Peninsula from Tuesday morning, all with a moderate chance of being upgraded to a warning.
- APL/additional reporting RNZ
