A weaker exchange rate more than offset lower world prices for most of the country's export commodities last month and pushed ANZ's commodity price index to within 6 per cent of its all-time high in local dollar terms.
In world price terms the ANZ index fell 3.7 per cent, led by declines in dairy products which make up 44 per cent of the index.
Whole milk powder and skim milk powder fell 9 and 8 per cent respectively, while beef dropped 7 per cent.
Butter, cheese, lamb, aluminium, apple and pelt prices also fell, but wool, kiwifruit, casein, seafood and log prices all improved.
When converted into significantly weaker kiwi dollars, the ANZ index rose 0.9 per cent last month, to a two-year high just 6 per cent off its all-time high in March 2011.
And in world price terms, even with last month's decline, the index is still the fourth highest on record.
ANZ chief economist Cameron Bagrie said the New Zealand dollar should remain strong: "The US dollar might have a firmer feel, but New Zealand still looks more solid than most in the growth and yield stakes."
High commodity prices provide an offset to the impact of the summer's drought, which the Treasury estimates will cut 0.7 percentage points off economic growth this year.
"Increasingly as drought concerns recede and milk production volumes recover in the new season, we expect world dairy prices to descend further from their April peak," said Westpac economist Nathan Penny. "However, with world production tight and Chinese demand robust, they will remain high by historical standards."
Bank of New Zealand economist Craig Ebert expects the terms of trade for the June quarter to be 3.5 per cent higher than a year ago, only a few per cent lower than the 37-year high recorded two years ago.