This year's drought may cost Northland dairy farmers about $500 million, says the Northland Rural Support Trust.
For months, the region has been gripped by its worst drought in 60 years - and it won't be officially lifted until September.
Trust member Julie Jonker says recent rain was welcome but more was needed.
Although heavy rain is forecast it may wash away any recent fertilisers farmers may have put on their land.
She said the estimated cost of the drought to dairy farmers alone in Northland was $500 million, and that would be even higher once costs of associated business was taken into account.