"The next few days will see a gradual warm-up, but long-range data suggests we may not be seeing many 30C-plus days coming up with highs mainly in the mid 20s," a Weatherwatch NZ spokesperson says.
"With a high pressure system rolling in this week, temperatures will return to normal for South Islanders.
"Overnight lows will be in the single digits for the next couple of nights but by the end of the week and weekend the humid noreast flow around New Zealand will see overnight lows in the mid teens and low 20s."
The North Island will be soon be back to high humidity thanks to a subtropical flow. Overnight temperatures will drop only a few degrees from daytime highs.
An easterly flow in northern New Zealand will kick in this week before a north-to-northeast flow at the weekend.
Winds may become quite brisk in exposed areas with rain in Northland heavy at times.
Weatherwatch polls indicate this summer has been much better than last year.
A poll in January last year revealed 61 per cent of respondents were disappointed with summer.
A poll on weatherwatch.co.nz shows a majority want cooler weather in February, although 13.5 percent want it to be even hotter.