No end in sight for North's heatwave

Allegra Austen-Reid is among thousands who have been flocking to water to cool down, as sweltering temperatures in Northland drive up humidity levels. Photo / Supplied

Temperatures in Northland have been above average this summer and weather boffins are predicting the high humidity will stick around for at least the rest of this month.

A slow-moving weak front over Northland is bringing warm and moist air and isolated showers throughout the region.

MetService forecaster Emma Blades said the system was driving humidity levels up.

Kerikeri Airport recorded a sweltering 27.6C on Sunday, Whangarei Airport 27.3C and Kaitaia 26.4C as people took to their favourite water spots to cool down.

"Currently humidity is around 90 per cent, with temperatures in Northland hovering in the mid to late 20Cs, and that's a lot of moisture in the air. With 100 per cent humidity, you will get a lot of rain," Ms Blades said.

She said although the humidity seemed unbearable to some people, it had not been overly humid.

"There's currently a northwesterly breeze and we have just had a series of ridges moving through, but the humidity would have been worse with northeast flows from the tropics, which we haven't had this year."

Ms Blades said the current humid weather condition would continue this week, with isolated showers except for Friday.

"A high pressure sitting over us means temperatures will be in the mid to late 20Cs over most of the North Island in January," she said.

Overnight temperatures in Northland will be about 10C lower than daytime figures. Showers with light to little winds are predicted for most of the region early next week, except Dargaville. According to MetService, a large ridge of high pressure should build over the South Island tomorrow, with a south to southeast flow over the North Island.

The ridge should move slowly northwards from Thursday.