A Northland dairy farmer estimates the drought is going to cost him hundreds of thousands of dollars this season in lost production and extra feed costs.
The region's daily milk production has dropped 29% below a year ago, as farmers cut back on milking and dry off cows because of the lack of feed.
Bruce Paton, who farms near Whangarei and has another farm on the west coast of Northland, says he has been able to keep his milk production within range of last year's, but it has been at a significant cost.
Mr Paton says in October last year the farm only averaged 30kg of dry matter growth, half the usual amount. In mid-December until now there has only been 10kg of growth - a third of the usual amount at that time.
He says the production of grass has been so drastically reduced it has put a lot of emphasis on supplements, so the costs have been dramatically increased.
In Waikato, daily milk production is down 6.5% compared with a year ago.