A climate scientist says the risk of drought in many parts of the country is likely to double by 2040.
Six regions in the North Island are officially declared in drought meaning extra government funding is available for harship assistance to farmers.
Northland, South Auckland, Waikato, Bay of Plenty, Coromandel and Hawke's Bay are covered by the Government declaration. Another two regions, Manawatu and Rangitikei, have asked the Government to declare a state of drought in their regions.
New models from the National Institute of Water and Atmospheric Research suggest that by the middle of the century most North Island regions, as well as those in eastern parts of the South Island, will spend up to 10% more of the year in drought.
Victoria University climate scientist James Renwick said droughts last for an average of a month per year at present, but that is likely to increase to more than two months a year because of climate change.