Most regions had above average temperatures and sunshine hours in December 2008.
The National Climate Centre says the national average temperature was 15.8 degrees, 0.2 degrees above average.
However, temperatures were below average in Northland and inland Canterbury.
NIWA climate scientist Andrew Tait says the dry weather was the result of a series of anti-cyclones, which are expected to continue over summer.
He says rain during December and early January helped some of the driest parts of the country.
Dr Tait says rainfall was above average for the month in lower Northland, Nelson, Marlborough, Banks Peninsula and inland Canterbury and Otago.
Of the five main centres Auckland was the warmest, Wellington was the wettest and Christchurch was the driest and sunniest.
