Weather: Temperatures to rise around New Zealand after cool start

New Zealand is in for a jump in temperatures as cool weather switches to warmer later in the week.

MetService says the week starts off cold, dry and clear with cooler air coming up from the Southern Ocean.

But the country gets warmer and wetter as the week progresses, with the eastern North Island reaching the higher 20s.

"A welcome period of dry weather is on tap for much of NZ through mid-week. Thereafter, more active weather is likely to return for the South, and especially, the North Island," NIWA says.

"While exact details will change, the 'flavour' will likely not. Have a look at the next two weeks."

Christchurch is forecast to go from daytime highs of 19C on Tuesday to 25C on Friday, and Napier is forecast to go from 20C on Tuesday to 27C on Saturday and Sunday.

Nelson will see its minimums increase from 9C to 15C throughout the week, while Blenheim will shift its minimums from 6C to 14C.

"The smoke from Australia also shouldn't be as bad this week in NZ although some airflows may drag it down towards the lower South Island where nor'west flows out of the eastern Aussie region may pop up at times," WeatherWatch says.

"Air pollution levels are 'good' right across New Zealand with much clearer skies today compared to just 24 to 48 hours ago."